A

This list contains acronyms, initialisms, and pseudo-blends that begin with the letter A.

For the purposes of this list:

acronym = an abbreviation pronounced as if it were a word, e.g., SARS = severe acute respiratory syndrome, pronounced to rhyme with cars
initialism = an abbreviation pronounced wholly or partly using the names of its constituent letters, e.g., CD = compact disc, pronounced cee dee
pseudo-blend = an abbreviation whose extra or omitted letters mean that it cannot stand as a true acronym, initialism, or portmanteau (a word formed by combining two or more words).

(a) = acronym, e.g.: SARS – (a) severe acute respiratory syndrome

(i) = initialism, e.g.: CD – (i) compact disc

(p) = pseudo-blend, e.g.: UNIFEM – (p) United Nations Development Fund for Women

(s) = symbol (none of the above, representing and pronounced as something else; for example: MHz – megahertz)

Some terms are spoken as either acronym or initialism, e.g., VoIP, pronounced both as voyp and V-O-I-P.

(Main list of acronyms)

a – (s) Atto-
A – (s) Ampere

A0–9

A1C – Airman First Class
A2ATD or A²ATD – (i) Anti-Armour Advanced Technology Demonstration
A2C2 or A²C² – (i) Army Airspace Command and Control
A3 – many, including a European larger than standard office paper size
A4 – many, including a European standard office paper size; see entry
A10 – (i) Atlantic 10 Conferencee

AA

aa – (s) Afar language (ISO 639-1 code)
aA – (s) Attoampere
AA
- (i) achieved availability
- Alcoholics Anonymous
- (s) Armed Forces Americas (postal symbol)
- Aruba (FIPS 10-4 territory code)
- (i) assembly area
- Automobile Association
- avenue of approach
- American Airlines
- Aerolíneas Argentinas
AAA
- (i) administration, authorization, and authentication
- American Automobile Association ("Triple-A")
- anti-aircraft artillery
- Amateur Athletic Association (of England)
- Asistencia Asesoría y Administración (Spanish, "Assistance, Consulting, and Administration" — original name of Mexican professional wrestling promotion Lucha Libre AAA Worldwide)
AAAI – (i) Association for the Advancement of Artificial Intelligence, formerly American Association for Artificial Intelligence
AAAS – (i) American Association for the Advancement of Science
AAAV – (i) Advanced Amphibious Assault Vehicle
AABN – (i) African Aurora Business Network
AABP – (i) American Association of Bovine Practitioners
AAC
- (i) American Athletic Conference
- Army Air Corps (British Army)
AACL – (i) Albanian American Civic League
AACCS – (i) American Association of Christian Colleges and Seminaries
AAD
- (i) analogue-analogue-digital (CD quality)
- Australian Antarctic Division
AADHD – Adult attention deficit hyperactivity disorder
AADT – (i) annual average daily traffic
AADAC – (a) Alberta Alcohol and Drug Abuse Commission
AADC
- (i) area air defense commander
- (i) amino acid decarboxylase
- (i) aromatic L-amino acid decarboxylase
- (i) Australian Antarctic Data Centre
AAFC
- (i) U.S. Army Air Corps Ferrying Command (1941–1942)
- All-America Football Conference (1946–1949)
AAFES – (i) Army and Air Force Exchange Service
AAI – (i) applied artificial intelligence
AAIS – (i) advanced airborne interceptor simulator
AAM – (i) air-to-air missile
AAMOF – (i) as a matter of fact
AAN – (i) American Academy of Nursing
AANEAS – (a) Anglo-Australian Near-Earth Asteroid Survey
AAODL – (i) Atmospheric Aerosols and Optics Data Library
a.a.p. – (i) Associated Artists Productions (former film distributor)
AAP
- (i) advanced acquisition plan
- Allied administrative publication
- American Academy of Pediatrics
AAPC – (i) Accounting and Auditing Policy Committee
aar – (s) Afar language (ISO 639-2 code)
AAR
- (i) after-action review
- Association of American Railroads
AARP – (i/s) American Association of Retired Persons (now officially known only by the initials)
AAS
- (i) Advanced Automation System
- American Astronomical Society ("double-A-S")
AASPEM – (i) advanced air-to-air system performance evaluation model
AAT – (i) Australian Antarctic Territory
AAV – (i) Amphibious Assault Vehicle
AAWC – (i) anti-air warfare commander

AB

ab – (s) Abkhaz language (ISO 639-1 code)
AB
- (i) Able Seaman (both the rank and the occupation)
- (s) Alberta (postal symbol)
ABA
- (i) Adriatic Basketball Association
- American Bar Association
- American Basketball Association
- American Beverage Association
- American Bicycle Association
- American Birding Association
- Australian Broadcasting Authority
ABB – (i) ASEA Brown Boveri (Swiss-Swedish multinational company)
ABBA – (a) Agnetha, Benny, Björn, Anni-Frid (Swedish pop group)
ABC
- (i) abstinence, be faithful, condoms
- Active Body Control
- airway, breathing, circulation (see CPR)
- Alcoholic Beverage Control (or Alcoholic Beverage Commission)
- alien big cat
- always be careful
- American Bird Conservancy
- American-born Chinese
- American Broadcasting Company
- anti-lock brake controller
- Associated British Cinemas
  - ABC Cinemas
  - ABC Weekend TV (Associated British Cinemas (Television) Ltd / ABC Television Ltd)
- Associated British Corporation (ABC Television Films Ltd)
- Atanasoff–Berry Computer
- Atlantic Baptist College
- atomic, biological, chemical (see NBC)
- Australian Broadcasting Corporation
- already been chewed gum
ABCA
- (i) American, British and Canadian Armies (originally)
- Army Bureau of Current Affairs
ABCS – (i) (U.S.) Army Battle Command System
ABET – (a) Accreditation Board for Engineering and Technology
ABFIST – (i) Advanced Bradley Full Crew Interactive Skills Trainer
ABGI – (i) Addington-Barker Group International
ABIN – (a) Agência Brasileira de Inteligência (Brazilian Intelligence Agency)
abk – (s) Abkhaz language (ISO 639-2 code)
ABL – (i) American Basketball League
ABLE
- (a) Achieving a Better Life Experience Act, a U.S. law that established tax-advantaged accounts for the benefit of individuals with disabilities
- AirBorne Law Enforcement (police air support unit)
ABM – (i) anti-ballistic missile – Asynchronous Balanced Mode – automated banking machine
ABMC – (i) American Battle Monuments Commission
ABN
- (i) Australian Business Number (a number issued by the Australian government as registration of a business and used for taxation purposes)
- Advance Beneficiary Notice of Non-coverage (a form used in health insurance)
ABPI – (i) Association of the British Pharmaceutical Industry
ABRSM – (a) Associated Board of the Royal Schools of Music
ABS
- (i) acrylonitrile butadiene styrene
- anti-lock braking system
ABSA – (a) Amalgamated Banks of South Africa ("ab-sa")
ABSTRIPS – (p) abstraction-based STRIPS
ABV – (i) Alcohol by volume
ABW – (s) Aruba (ISO 3166 trigram)

AC

aC – (s) Attocoulomb
Ac – (s) Actinium
AC
- (i) Adriamycin-Cyclophosphamide (chemotherapy)
- Air Conditioning
- Aircraftman
- Alternating Current
- Altocumulus
- ante Christum (Latin, "before Christ"; see BC)
- ante cibum (Latin, "before meals")
- (s) Antigua and Barbuda (FIPS 10-4 country code)
- (i) Associazione Calcio (Italian, "football (soccer) club")
A/C – (i) Air Conditioned/Conditioning – Aircraft
AC1 – Aircraftman 1st Class
AC2 – Aircraftman 2nd Class
ACA
- Affordable Care Act, shorthand for the Patient Protection and Affordable Care Act, commonly called "Obamacare"
- (i) Airspace Control Authority
- Airspace Co-ordination Area
- A Current Affair
ACAB, short for "All Cops Are Bastards"; used as a political slogan associated with dissidents who are opposed to the police.
ACARS – (a) Aircraft Communications Addressing and Reporting System
ACAS
- (a) Aboriginal Children's Advancement Society
- Advisory, Conciliation and Arbitration Service
ACB – (i) Asociación de Clubes de Baloncesto (Spanish for "Association of Basketball Clubs")
ACC
- (i) U.S. Air Combat Command
- Air Component Commander
- Alpine Club of Canada
- Altocumulus castellanus
- Area control center
- Atlantic Coast Conference
- Automatic climate control
ACCA
- (i) The Association of Chartered Certified Accountants
- Automatic Cloud Cover Assessment
ACCAC – (a) Awdurdod Cymwysterau, Cwricwlwm ac Asesu Cymru (Qualifications, Curriculum and Assessment Authority for Wales)
ACCD – American Coalition of Citizens with Disabilities
ACCS – (i) Air Communications and Control Squadron
ACDA – (i) Arms Control & Disarmament Agency
ACDC
- (i) Alternating Current Direct Current
- the name of an Australian rock music band
- a term for a bisexual person
A/Cdre – Air Commodore
ACDT
- (a) Apple Certified Desktop Technician
- (a) Australian Central Daylight Time
ACE
- (a) Air Combat Emulator (computer game)
- Allied Command Europe
- Angiotensin-converting enzyme
- Armored Combat Earthmover
- Automatic Computing Engine
ACE2 – (i/p) Angiotensin-converting enzyme 2 (pronounced "ace-two")
ACES
- (a) Aerolíneas Centrales de Colombia (Spanish, "Central Colombian Airlines")
- Auxiliary Campus Enterprises and Services of Alfred State College
ACF
- (i) Administration for Children and Families
- American Car and Foundry
- American Culinary Federation
ACH – (i) Automated clearing house
ACHT – (i) Average Call Hold Time
ACID – (a) Atomicity, Consistency, Isolation, and Durability (in databases)
ACINT – (p) Acoustic Intelligence
ACK – (p) Acknowledge (telecommunications; cf. NAK)
ACL
- (i) Access Control List
- Anterior cruciate ligament; the initialism can also refer to an injury to this ligament
- Atlantic Coast Line Railroad
ACLJ – (i) American Center for Law and Justice
ACLOS – (i) Automatic CLOS (missile control system)
ACLS – (i) American Council of Learned Societies
ACLU
- (i) American Civil Liberties Union
- American Communist Lawyers Union (pejorative slang for the above)
ACM – many, including Association for Computing Machinery; see entry
ACMC – (i) (U.S.) Assistant Commandant of the Marine Corps
ACN
- (i) Airborne Communications Node
- Australian Company Number (number issued by the Australian government as registration of a limited liability company)
ACNA – (i) Anglican Church in North America
ACO – (i) Airspace Control Order
ACOBA – (a) Advisory Committee on Business Appointments
ACOG – (a) American College of Obstetricians and Gynecologists
ACOM – (p) (U.S.) Atlantic Command
ACORN – (a) Association of Community Organizations for Reform Now
ACP
- (i) African, Caribbean and Pacific Group of States
- Air Control Point
ACR – (i) Advanced Concepts and Requirements
ACRI – (p) African Crisis Response Initiative
ACRT – (i) Advanced Concepts Research Tool simulator
ACS
- (i) Affiliated Computer Services (NYSE ACS)
- Alaska Communications Service
- American Cancer Society
- American Chemical Society
- Association of Caribbean States
- Australian Computer Society
ACSC – (i) Army Command and Staff College (various nations)
ACST – (i) Australian Central Standard Time
ACST – (i) American Cooperative School of Tunis
ACT
- (i) Adaptive Control of Thought (cognitive model)
- American College Test (ing Program)
- Australian Capital Territory (also postal symbol)
ACT UP – (a) AIDS Coalition to Unleash Power
ACTD – (i) Advanced Concept Technology Demonstration
ACTF
- (i) (U.S.) Army Constructive Training Federation
- Australian Children's Television Foundation
ACT-R – (i) ACT-Rational (cognitive model)
ACT-R/PM – (i) ACT-R/Perceptual-Motor (cognitive model)
ACTU – (i) Australian Council of Trade Unions
ACU
- (i) Abilene Christian University
- American Conservative Union
ACUF
- (i) BGN Advisory Committee on Undersea Features
- (a) American Conservative Union Foundation
ACV – (i) Armoured Combat Vehicle

AD

AD – (i) Air Defence – (s) Andorra (ISO 3166 digram) – (i) Anno Domini (Latin, "In the year of our Lord")
A/D – (i) Analog/Digital
ADA
- (i) Air Defence Artillery
- American Dental Association
- Assistant District Attorney
- Americans with Disabilities Act (see also the similar but non-acronymic Ada programming language)
- ADA Cryptocurrency token for Cardano blockchain
ADAC – (a/i) Allgemeiner Deutscher Automobil-Club (German, "General German Automobile Club")
ADAGE – (a) Air Defense Air to Ground Engagement (simulation)
ADAP – (i) AIDS Drug Assistance Program
ADAS – (a/i) Asiago-DLR Asteroid Survey
ADAT – (i) Alesis Digital Audio Tape (recording format)
ADatP – (p) Automated Data Processing
ADATS –
- (i) Agricultural Development and Training Society
- Air Defence Anti-Tank System
- Australian Defence Air Traffic System
ADB – (i) Asian Development Bank
ADB- All da best/All the best - texting slang
ADC –
- (i) Aide De Camp
- U.S. Air Defense Command (1946–1992)
- Apple Display Connector
ADCTS – (i) Advanced Distributed Combat Training System
ADD –
- (i) Analog Digital Digital (CD quality)
- Attention-Deficit Disorder
- Administration on Developmental Disabilities
ADDIE – (i) Analyze Design Develop Implement and Evaluate
ADDNS – (i) Advanced Deployable Day/Night Simulation
ADE
- (i) Algebraic differential equation
- Antibody-dependent enhancement
ADF
- (i) Australian Defence Force
- African Development Foundation
ADGB – Air Defence of Great Britain
ADHD – (i) Attention-Deficit Hyperactivity Disorder
ADHS – (i) Attention-Deficit Hyperactivity Syndrome
ADI – (i) Acceptable/Allowable Daily Intake
ADIZ – (a/i) Air Defence Identification Zone
ADL – (i) Anti-Defamation League
ad loc. – (p) ad locum (Latin, "to/at the place")
ADM –
- (i) Administrative
- (s) Admiral, and the U.S. Public Health Service Commissioned Corps
- Archer Daniels Midland
- Assistant Deputy Minister
ADOA – (a/i) Air Defence Operations Area
ADP –
- (i) Adenosine DiPhosphate
- Army Doctrine Publication (UK, Canada, Australia)
- Automatic/Automated Data Processing
ADRG – (p) Arc-second Raster Chart (ARC) Digitized Raster Graphics
ADS –
- (a/i) Active Denial System
- Astrophysics Data System
- Attention Deficit Syndrome
ADSR – (i) Attack, Decay, Sustain, Release (sound envelope specification)
ADT
- (i) Abu Dhabi Terminals, operator of commercial ports in Abu Dhabi
- American District Telegraph, a former name of ADT Inc.
- Atlantic Daylight Time (UTC−3 hours)
ADTB – (i) Army Doctrine and Training Bulletin
adv. – (p) adversus (Latin, "against")
ADW – (i) Air Defence Warning

AE

ae – (s) Avestan language (ISO 639-1 code)
AE
- (s) Armed Forces Africa/Canada/Europe/Middle East (postal symbol)
- United Arab Emirates (ISO 3166 digram; FIPS 10-4 country code)
- (i) Artix Entertainment
- American Eagle
A&E
- (a/i) Arts & Entertainment Network, the original name for the U.S. TV channel now known as A&E Network
- Accident and Emergency
AEB – Autonomous Emergency Braking, see Collision avoidance system
AED – (s) United Arab Emirates dirham (ISO 4217 currency code)
AEDT – (a) Australian Eastern Daylight Time
AEF – (i) American Expeditionary Force
AEGIS – (p) Airborne Early warning Ground environment Interface Segment (fake etymology)
AEI-T – (i) Army Enterprise Infostructure-Transport
aeq. – (p) aequalis (Latin, "equal")
AESR – (i) Aeronautical Equipment Service Record
AEST – (a) Australian Eastern Standard Time
aet. – (p) aetatis (Latin, "of age", "aged")
aet – (i) After extra time (Football)
AEW
- (i) Air Expeditionary Wing
- (i) Airborne early warning
- (i) Airborne electronic warfare
- (i) All Elite Wrestling (US professional wrestling promotion)

AF

af – (s) Afrikaans language (ISO 639-1 code)
aF – (s) Attofarad
AF
- (s) Afghanistan (FIPS 10-4 country code; ISO 3166 digram)
- (i) Air Force
- As fuck
AFA
- (i) U.S. Air Force Academy
- Asociación del Fútbol Argentino (Spanish, "Argentine Football Association")
AFAIC – (i) As Far As I'm Concerned
AFAICT – (i) As Far As I Can Tell
AFAIK – (i) As Far As I Know
AFAIR – (i) As Far As I Remember/Recall
AFAM
- (i/a) Associazione Friulana di Astronomia e Meteorologia (Italian, "Friuli Association of Astronomy and Meteorology")
- (p) Department of African and Afro-American Studies, University of North Carolina at Chapel Hill — notable for its links to the school's academic-athletic scandal in the 2010s
AFATDS – (i) Advanced Field Artillery Tactical Data System
AFC
- (i) American Football Conference
- Approved for construction
- Asian Football Confederation
AFCEA – (i) Armed Forces Communications and Electronics Association
AfD
- (i) Allianz für Deutschland ("Alliance for Germany"), former political alliance in East Germany
- Alternative für Deutschland ("Alternative for Germany"), current German political party
AFD
- (i) Active Format Description, a technical standard for TV or set-top box decoders
- Advanced Format Drive, a type of computing storage device
- Adjustable-frequency drive
- Adult Film Database, web-based database of adult cinema
- Agence française de développement ("French Development Agency"), a French international development agency
- Alliance des forces démocratiques (French; "Alliance of Democratic Forces"), an Ivorian political alliance
- Alliance for Freedom and Democracy, an Eritrean political party
AFDB – (i) African Development Bank
AFES – (i) Automatic Fire Extinguishing System
AFG – (s) Afghanistan (ISO 3166 trigram)
AFGAM – (i) Amazon Facebook Google Apple Microsoft
AFI
- (s) French Territory of the Afars and Issas (ISO 3166 trigram; obsolete since 1977)
- (i) "Agencia Federal de Investigaciónes" (México)
AFIS
- (a) Automated Fingerprint Identification System
- American Forces Information Service
AFIST – (i) Abrams Full Crew Interactive Skills Trainer
AFJ – (i) April Fool's Joke
AFK – (i) Away From Keyboard (Internet chat abbreviation)
AFL
- (i) American Federation of Labor
- American Football League — either the 1960s league that merged into the National Football League, or one of several other leagues of American football
- Arena Football League
- Australian Football League
AFL–CIO – (i) American Federation of Labor – Congress of Industrial Organizations
AFLAC – (a) American Family Life Assurance Company of Columbus
AFM – (i) Army Field Manual (UK; the U.S. more frequently uses just FM) – Atomic Force Microscope – Aviation Fleet Maintenance
AFN – (s) Afghani (ISO 4217 currency code)
AFO – (i) Association of Field Ornithologists
AFOSR – (i) U.S. Air Force Office of Scientific Research
AFP
- (i) Agence France-Presse (French, "French Press Agency")
- Australian Federal Police
AFQT – (i) Armed Forces Qualification Test
afr – (s) Afrikaans language (ISO 639-2 code)
AFRC – (i) Air Force Reserve Command
AFRL – (i) Air Force Research Laboratory
AFROTC – (i) Air Force Reserve Officer Training Corps
AFRRI – (i, U.S.) Armed Forces Radiobiology Research Institute
AFRTS – (i) Armed Forces Radio and Television Service
AFS
- (i) Active Front Steering
- Air Facility Sub-System
- Amniotic Fluid-derived Stem cell
AFS&A or AFSA – (i) U.S. Air Force Studies and Analysis
AFSC
- (i) U.S. Air Force Staff College (obsolete; replaced by JFSC)
- U.S. Air Force Systems Command
AFSCN – (i) U.S. Air Force Satellite Control Network
AFSPC – (i) Air Force Space Command
AFT – American Farmland Trust
AFV – (i) armoured fighting vehicle or America's Funniest Home Videos
AFWA
- (a) Air Force Weather Agency
- Association of Fish and Wildlife Agencies

AG

ag – (s) Attogram
Ag – (s) Silver (Latin argentum)
AG
- (i) air gunner
- Aktiengesellschaft (German, "incorporated")
- (s) Algeria (FIPS 10-4 country code)
- Antigua and Barbuda (ISO 3166 digram)
- Assemblies of God
AGA
- (a/i) AB Gas-accumulator ("ah-gah", Swedish company)
- Advanced Graphics Architecture
AGARD – (a) Advisory Group for Aerospace Research and Development
AGARDograph – (p) Advanced Guidance for Alliance Research and Development publication
AGASA – (a) Akeno Giant Air Shower Array (cosmic ray detector)
AGB – (i) Internal Nintendo initialism (Advanced Game Boy) for Game Boy Advance
AGC
- (i) Apollo Guidance Computer
- Automatic Gain Control
AGC – (i) Adjutant General's Corps (British Army)
AGDC – (i) Australian Game Developers' Conference
AGI – (i) Auxiliary Group Intelligence
AGL – (i) Above Ground Level
AGM – (i) Annual General Meeting
AGN – (i) Active Galactic Nucleus
AGO – (s) Angola (ISO 3166 trigram)
AGP – (i) Accelerated Graphics Port
AGRICOLA – (a) Agriculture Online Access
AGS – (i) Alaska Ground Station (LandSat)
AGTS – (i) Advanced Gunnery Training System
AGU – (i) American Geophysical Union
AGW – (i) Autonomous Guided Weapon

AH

aH – (s) Attohenry
Ah – (s) Ampere hour
AH – (i) Attack Helicopter
AHA – (i) American Heart Association
AHCPR – (i) Agency for Health Care Policy and Research (obsolete; replaced with AHRQ)
AHEC – (i) Australian Health Ethics Committee
AHPCRC – (i) Army High Performance Computing Research Center
AHQ – Air Headquarters
AHRQ – (i) Agency for Healthcare Research and Quality
AHS – (i) American Housing Survey

AI

AI
- (i) Air Interdiction
- Amnesty International
- Artificial Insemination
- Artificial Intelligence
- (s) Anguilla (ISO 3166 digram)
AIA
- (i) Aerospace Industries Association
- American Institute of Architects
- (s) Anguilla (ISO 3166 trigram)
AIAA – (i) American Institute of Aeronautics and Astronautics
AIC
- (i) African Independent Church
- Animal Identification Coordinator
AICD – (i) Australian Institute of Company Directors
AICMFP – (i) And I Claim My Five Pounds
AID – (i) U.S. Agency for International Development
AIDS – (a) Acquired Immune Deficiency Syndrome
AIHW – Australian Institute of Health and Welfare
AIM – many, including AOL Instant Messenger, Australian Institute of Management; see entry
AIMP – (i) Aurora Incremental Modernization Project
AIPAC – (i) American Israel Public Affairs Committee
AIR – (i) Aircraft Inventory Record
AIRFA – (a) American Indian Religious Freedom Act
AIRS – (a/i) Aerometric Information Retrieval System (obsolete; replaced with AFS)
AIS
- (i) Australian Institute of Sport
- Automatic Identification System
AISB – (i) (British) Society for the Study of Artificial Intelligence and the Simulation of Behaviour

AJ

aJ – (s) Attojoule
AJ – (s) Azerbaijan (FIPS 10-4 country code)
Ajax – (a) Asynchronous JavaScript And XML
AJD – (i) Astronomical Julian day
AJP – (i) Allied Joint Publication
AJPW – (i) All Japan Pro Wrestling

AK

ak – (s) Akan languages (ISO 639-1 code)
aK – (s) Attokelvin
AK – (s) Alaska (postal symbol)
aka – (s) Akan languages (ISO 639-2 code)
a.k.a. – (i) Also known as (i.e.: alias)
AKA – (i) Above knee amputation (orthopaedic usage)
AKDT – (p) Alaska Standard Daylight Saving Time (UTC−8 hours)
AKST – (p) Alaska Standard Time (UTC−9 hours)
AKP – (i) Adalet ve Kalkınma Partisi (Turkish, "Justice and Development Party")

AL

aL – (s) Attolitre
Al – (s) Aluminium
AL
- (s) Alabama (postal symbol)
- Albania (FIPS 10-4 country code; ISO 3166 digram)
- (i) Anno Lucis (Latin, "Year of Light", in Masonic tradition, most often seen on plaques bearing the founding dates of buildings, in years AD and years AL)
ALA – (s) Åland (ISO 3166 trigram)
ALAP – (a) As Long/Late As Possible
ALARM – (a) Air-Launched Anti-Radar Missile
ALB – (s) Albania (ISO 3166 trigram)
ALCOA or Alcoa – The Aluminum Company of America, NYSE:AA
ALD – (i) Accounting Line Designator (nuclear weapon targeting)
ALERT – (a) Advanced Linked Extended Reconnaissance and Targeting – Attack and Launch Early Reporting to Theatre
ALF
- (a) Africa Leadership Forum
- Alien Life Form (cf. ALF (TV series))
- Animal Liberation Front
ALG – (s) Algeria (IOC and FIFA trigram, but not ISO 3166)
ALGOL – (p) ALGOrithmic Language
ALL – (s) Albanian lek (ISO 4217 currency code)
ALOA – (i) Associated Locksmiths of America, Inc.
ALOC
- (a) Air Lines Of Communication
- (a) Average Length of Calls
ALP – (i) Australian Labor Party
ALPA – (a) Air Line Pilots Association
ALS – (i) Amyotrophic Lateral Sclerosis – Automatic Landing System
ALSHS – (a) Abraham Low Self-Help Systems
ALSP – (i) Aggregate Level Simulation Protocol
ALTA – American Land Title Association
ALTE – (a) Association of Language Testers in Europe
ALTACS – (p) Automated decision Logic Tactical Air Combat Simulation

AM

am
- (s) Amharic language (ISO 639-1 code)
- Attometre
Am – (s) Americium
AM
- many, including Amplitude Modulation and Ante Meridiem; see entry
- (s) Armenia (FIPS 10-4 country code; ISO 3166 digram)
AM1 – Airman 1st class
AMA
- (i) American Medical Association
- Australian Medical Association
AMAPS – (a) Aircraft, Missile, Avionics Performance Simulation
AMC
- (i) Adaptive modulation and coding (digital communications)
- U.S. Air Mobility Command
- American Motors Corporation
- American Movie Classics (TV network; now known simply by the initials)
- U.S. Army Materiel Command
AMCB – (i) U.S. Army/Marine Corps Board
AMD
- (i) Advanced Micro Devices
- Age-related Macular Degeneration
- (s) Armenian dram (ISO 4217 currency code)
AMF – (i) Afghan Military Force(s)
AMFOM – (i) Advanced Missile Fly Out Model ("am-fomm")
AMFR
- (i) Age-specific Marital Fertility Rate
- Amplitude Modulation Following Response
AMFRS
- (i) Advanced Multi-Function Radio Frequency System
- Automatic Multisensor Feature-based Recognition System
amh – (s) Amharic language (ISO 639-2 code)
AML – (i) Acute Myeloid Leukaemia
AMLCD – (i) Active Matrix Liquid Crystal Display
AMLO
- (i) Andrés Manuel López Obrador (Mexican politician)
- Anti-Money Laundering Office — separate government agencies in Taiwan and Thailand
AMO – (i) Atlantic Multidecadal Oscillation
AMOLED – (i) Active-matrix organic light-emitting diode
AMOS
- (a) Advanced MOrtar System
- Air Force Maui Optical and Supercomputing observatory
AMP
- (i) Adenosine MonoPhosphate
- Automated Mission Planner
- Anak ng Puta
- (i) Ain't My Problem
AMRAAM – (a) Advanced Medium-Range Air-to-Air Missile
AMRDEC – (i) U.S. Aviation & Missile Research, Development, & Engineering Center
AMS
- (i) Agriculture Marketing Service
- American Mathematical Society
AMSAA – (i/a) U.S. Army Materiel Systems Analysis Activity
AMSB – (i) Aix Maurienne Savoie Basket (French basketball club)
AMSO – (i/a) U.S. Army Model and Simulation Office
AMSU – Advanced Microwave Sounding Unit
AMTE – (i) UK Admiralty Marine Technology Establishment (1977–1984)

AN

an – (s) Aragonese language (ISO 639-1 code)
aN – (s) Attonewton
AN
- (s) Andorra (FIPS 10-4 country code)
- Netherlands Antilles (ISO 3166 digram)
ANA
- (i) Administration for Native Americans
- Afghan National Army
- All Nippon Airways
- Anti-Nuclear Anti-body
- (a) Australian National Airways
- Australian Natives' Association
ANC – (i) African National Congress
AND – (s) Andorra (ISO 3166 trigram)
ANFO – (i) Ammonium nitrate/fuel oil (explosive)
ANG
- (i) Air National Guard
- (s) Angola (IOC and FIFA trigram, but not ISO 3166)
- (s) Netherlands Antillian guilder (ISO 4217 currency code)
ANGLiCo – (p) Air/Naval Gunfire Liaison Company
ANL – (i) Argonne National Laboratory
ANM – (i) Acoustic Noise Monitor
ANOVA – (p) ANalysis Of VAriance
ANS – (i) Applied and Natural Sciences
ANSI – (a) American National Standards Institute
ANTM – (i) America's Next Top Model
ANT
- (s) Netherlands Antilles (ISO 3166 trigram)
- Antigua and Barbuda (IOC trigram, but not ISO 3166 or FIFA)
ANTY – Acronyms, No Thank You
ANWA – (i) Augusta National Women's Amateur, a prominent American golf tournament
ANWR – (i) Arctic National Wildlife Refuge /ˈænwɑːr/
ANZ – (s) Australia and New Zealand Banking Group
ANZAC – (a) Australian and New Zealand Army Corps

AO

AO
- (s) Angola (FIPS 10-4 country code; ISO 3166 digram)
- (i) Approach Officer (submarine)
- Area of Operations
AOA
- (i) Air Officer in charge of Administration
- Argonne National Laboratory
- (s) Angolan kwanza (ISO 4217 currency code)
- (i) Award of Arms (heraldry)
- Angle of Attack (fluid dynamics)
AOC
- (i) Air Operations Centre
- Air Officer Commanding
- Alexandria Ocasio-Cortez (American politician)
AOC in C – Air Officer Commanding in Chief
AOD – (i) Adrenalin O.D. (punk rock band)
AOE – Area of Effect
AOI
- (i) Angle of Incidence
- Arab Organization for Industrialization
AOL – (i) America OnLine
AOR – (i) Area of Responsibility
AOSTH – (i) Adventures of Sonic the Hedgehog
AOTS – (i) Attack of the Show!
AOU – (i) American Ornithologists' Union

AP

AP
- (i) Advanced Placement
- Air Publication
- (s) Andhra Pradesh (Indian state code)
- (s) Armed Forces Pacific (postal symbol)
- (i) Associated Press
- Auto Pilot
APA –
- (i) Acolytes Protection Agency (professional wrestling tag team)
- American Psychiatric Association
- American Psychological Association (see also APA style, a writing format developed by this body)
APB – (i) All Points Bulletin (police jargon)
APC
- (i) Armoured Personnel Carrier
- Armour Piercing Capped (ammunition)
APEC – (a) Asia Pacific Economic Cooperation
APCNR – (i) Armour-Piercing, Composite Non-Rigid (ammunition)
APCR – (i) Armour-Piercing, Composite Rigid (ammunition)
APDS – (i) Armour-Piercing, Discarding-Sabot (ammunition)
APEDS – (a) AMSAA Performance Estimates Data System
APEX – (p) Applied Physics Express
APFSDS – (i) Armour-Piercing, Fin-Stabilised, Discarding Sabot (ammunition)
APHA – (i) American Public Health Association
APHE – (i) Armour-Piercing, High Explosive (ammunition)
APHIS – (a) Animal and Plant Health Inspection Service
API – (i) Application Programming Interface
APL
- (i) A Programming Language
- Acute Promyeloid Leukaemia
- Anti-Personnel Landmine
- Applied Physics Laboratory (Johns Hopkins University)
APM – (i) Advanced Power Management
APNP – Advanced Practice Nurse Prescriber
APOD – (i) Aerial Port (Airport) Of Debarkation
APOE – (i) Aerial Port (Airport) Of Embarkation
APOLLO – (a) Apache Point Observatory Lunar Laser-ranging Operation
APP – (i) Allied Procedural Publication
APR – (i) Annual Percentage Rate
APS
- (i) Advanced Photo System (cf. APS-C, an image sensor format based on the size of the original APS film frame)
- American Physical Society
- Antiphospholipid Antibody Syndrome

AQ

AQ
- (i) AdventureQuest
- (s) American Samoa (FIPS 10-4 territory code)
- Antarctica (ISO 3166 digram)
- (i) Automatic qualifier, a term used by U.S. sports media from 1998 to 2013 to refer to the six conferences whose champions automatically entered the now-defunct Bowl Championship Series of college football
AQIM – (i) Al-Qaeda in the Islamic Maghreb
AQPS – (i) Autre que pur-sang (French: "Other than Thoroughbred"), designation of a type of French racehorse

AR

ar – (s) Arabic language (ISO 639-1 code)
Ar – (s) Argon
AR
- (s) Argentina (FIPS 10-4 country code; ISO 3166 digram)
- Arkansas (postal symbol)
- (i) ArmaLite Rifle (cf. ArmaLite AR-15 and AR-15 style rifle, both also referred to with the "AR" initialism)
- Armour
- (s) Arunachal Pradesh (Indian state code)
ara – (s) Arabic language (ISO 639-2 code)
ARAG – (a) Advanced Research and Assessment Group
ARB – (i) Administrative Review Board
ARBA – (a/i) Army Review Boards Agency
ARC
- (i) Appalachian Regional Commission
- Arc-second Raster Chart
- (a) Association of Retarded Citizens, the original name of the organization now known as Arc of the United States
- (i) Athletics–Recreation Center, an indoor arena at Valparaiso University
ARCA – (a) Automobile Racing Club of America
ARCENT – (p) United States Army Central Command
ARDA – (a) Advanced Research and Development Activity (became DTO 2006)
ARE
- (i) UK Admiralty Research Establishment (1984–1991)
- (s) United Arab Emirates (ISO 3166 trigram)
ARF – (i) ASEAN Regional Forum
arg – (s) Aragonese language (ISO 639-2 code)
ARG – (s) Argentina (ISO 3166 trigram)
ARH – (s) Armed Reconnaissance Helicopter
ARI
- (i) Acute Respiratory Infection
- U.S. Army Research Institute for the Behavioral and Social Sciences
ARL
- (i) UK Admiralty Research Laboratory (1921–1977)
- U.S. Army Research Laboratory
- UIUC Aviation Research Laboratory
ARM
- (a) Acorn RISC Machine, later Advanced RISC Machine (cf. Arm Ltd.)
- Anti-Radiation Missile
- Adjustable-rate mortgage
- (s) Armenia (ISO 3166 trigram)
ARNet – (p) Acquisition Reform Network
AROTS – Australian Rare Or Threatened Species
ARP – (i) Address Resolution Protocol – Applied Research Programme
ARPA – (a) Advanced Research Projects Agency
ARRC – (i) ACE Rapid Reaction Corps
ARRF – (i) Allied Rapid Reaction Force
ARRL – (i) American Radio Relay League
ARS
- (i) Agricultural Research Service
- (s) Argentine peso (ISO 4217 currency code)
ARSC – (i) Arctic Region Supercomputing Center
ARSPACE – (p) U.S. Army Space Command
ART
- (a) Adaptive Resonance Theory
- Anti-Retroviral Therapy
ARTCC – (i) Air Route Traffic Control Center
ARWG – (i) Army Research Working Group ("are-wig")

AS

as
- (i) Adult swim
- (s) Assamese language (ISO 639-1 code)
- Attosecond
aS – (s) Attosiemens
As – (s) Arsenic
AS
- (s) American Samoa (postal symbol; ISO 3166 digram)
- Australia (FIPS 10-4 country code)
- Assam / Asom (Indian state code)
- Advanced Subsidiary (Subsidiary version of Advanced Level, 'A'-Level)
AS – (i) ActionScript
A/S – (i) Anti-submarine
A&S – (i) Armament & Standardisation
ASA
- (i) AcetylSalicylic Acid
- American Standards Association
- Army Security Agency
- Atlantic Southeast Airlines
- Alaska Airlines (ICAO code)
ASAP – (a) As Soon As Possible
ASARS
- (a) Advanced Synthetic Aperture Radar System
- Airborne Search and Rescue System
ASB – (i) Associated Student Body – Alternative Service Book (Church of England)
asbl – (i) association sans but lucratif (French "Non-profit organisation")
ASBO – (a) Antisocial Behavior Order
ASCAP – (a) American Society of Composers, Authors, and Publishers
ASCC
- (i) Army Service Component Commander
- Automatic Sequence Controlled Calculator
- Air Standardization Coordinating Committee
ASCIET – (i) All Services Combat Identification Evaluation Team
ASCII – (a) American Standard Code for Information Interchange
ASC+T – (i) Anti Slip Control + Traction
ASD
- (i) (U.S.) Assistant Secretary of Defense
- Autism spectrum disorder
ASD(C3I) – (i) (U.S.) (Command, Control, Communications, & Intelligence)
ASD(FMP) – (i) (U.S.) Assistant Secretary of Defense (Force Management Policy)
ASD(HA) – (i) (U.S.) Assistant Secretary of Defense (Health Affairs)
ASD(ISA) – (i) (U.S.) Assistant Secretary of Defense (International Security Affairs)
ASD(ISP) – (i) (U.S.) Assistant Secretary of Defense (International Security Policy)
ASD(LA) – (i) (U.S.) Assistant Secretary of Defense (Legislative Affairs)
ASD(PA) – (i) (U.S.) Assistant Secretary of Defense (Public Affairs)
ASD(RA) – (i) (U.S.) Assistant Secretary of Defense (Reserve Affairs)
ASD(SO&HA) – (i) (U.S.) Assistant Secretary of Defense (Special Operations & Humanitarian Assistance)
ASD(SO/LIC) – (i) (U.S.) (Special Operations & Low-Intensity Conflict)
ASD(S&R) – (i) (U.S.) Assistant Secretary of Defense (Strategy & Requirements)
ASD(S&TR) – (i) (U.S.) Assistant Secretary of Defense (Strategy & Threat Reduction)
ASDIC – (a) Allied Submarine Detection Investigation Committee (Sonar)
ASEAN – (a) Association of Southeast Asian Nations
ASFAR – (a) Americans for a Society Free of Age Restrictions
ASG – (i) Area Support Group
ASIC – (a) Australian Securities & Investments Commission – (a) Aviation Security Identification Card
ASICS – (a) Anima sana in corpore sano (Latin, "A sound mind in a sound body") (athletic shoe manufacturer)
ASIO
- (a) Australian Security Intelligence Organisation
- Audio Stream Input/Output
ASIP
- (i) Advanced System Improvement Program
- Army Stationing and Installation Plan
- Application-specific instruction set processor
ASL
- (i) Above Sea Level
- American Sign Language (also known as Ameslan)
- "Age, Sex, Location?" (Internet slang)
asm – (s) Assamese language (ISO 639-2 code)
ASM
- (i) Air-to-Surface Missile
- (s) American Samoa (ISO 3166 trigram)
- (i) American Society for Metals
- American Society for Microbiology
- Association Sportive Montferrandaise (French, "Clermont-Ferrand Sporting Association"), as in ASM Clermont Auvergne
ASMB
- (i) American Society for Matrix Biology
- Adult Swim Message Board
ASME
- (i) American Society of Mechanical Engineers
- American Society of Magazine Editors
ASMP
- (i) Air-Sol Moyenne Portée missile (French "Medium-range air to surface")
- (p) Asymmetric multiprocessing
ASMR – Autonomous Sensory Meridian Response
ASN – (i) Associate of Science in Nursing
ASOC
- (a/i) Air Sovereignty Operations Centre
- Air Support Operations Centre
- Airport Security and Operations Centre
- Antarctic and Southern Ocean Coalition
- Atlanta Symphony Orchestra Chorus
- Australian Standard Offence Classification
ASP
- (i) Active Server Pages
- American Society of Primatologists
- Ammunition Supply Point
- Application Service Provider (cf internet service provider)
- Astronomical Society of the Pacific
- Association of Surfing Professionals
ASPI – (i) Australian Strategic Policy Institute
ASR
- (i) Alkali-silica reaction
- Anti Slip Regulation
ASRAAM – (a) Advanced Short-Range Air-to-Air Missile
ASSC – (i) Association for the Scientific Study of Consciousness
Ass Paym – Assistant Paymaster
AST – (i) Atlantic Standard Time (UTC−4 hours)
ASTIA – (a) Armed Services Technical Information Agency
ASTM – (i) American Society for Testing and Materials
ASTREA – (a) Aerial Support To Regional Enforcement Agencies (sheriff's air support unit)
ASUN – (p) Atlantic Sun Conference, now branded as the ASUN Conference (pronounced "A-sun")
ASUW – (p) AntiSUrface Warfare
ASVAB–Armed Services Vocational Aptitude Battery (taken by juniors in high school in the USA)
ASVEL – (a) Association Sportive Villeurbanne Éveil Lyonnais (Association Sportive is French for "Sporting Association"; the club was founded through the merger of AS Villeurbanne and Éveil Lyonnais)
ASW – (i) AntiSubmarine Warfare
ASWORG – (i) (U.S.) AntiSubmarine Warfare Operations Research Group
ASX
- (p) Advanced Stream Redirector
- Australian Securities Exchange

AT

aT – (s) Attotesla
At – (s) Astatine
AT – (i) Anti-Tank – (s) Ashmore and Cartier Islands (FIPS 10-4 territory code) – Austria (ISO 3166 digram) – (i) Advanced Technology (IBM Personal Computer/AT)
ATA – (i) Advanced Technology Attachment (IBM Personal Computer) – Afghan Transitional Authority – Allen Telescope Array – (s) Antarctica (ISO 3166 trigram)
ATAC – (a) Air Transportable Acoustic Communications
ATACMS – (p) Army TACtical Missile System
ATAPI – (a) Advanced Technology Attachment Packet Interface
ATAS – (a) Air-To-Air Stinger (missile)
ATAT – (a) Aiken Tactical Airsoft Team / Star Wars vehicle
ATB
- (i) Active Time Battle
- (s) British Antarctic Territory (ISO 3166 trigram; merged with AQ in 1979)
ATC –
- (i) Air Traffic Control
- Air Training Corps
- U.S. Air Transport Command (1942–1948)
- Athletic Trainer, Certified (www.nata.org)
ATCCIS – (i) Army Tactical Command and Control Information System
ATEBAWLS – (a) Association Towards Engineers Balling at Wii Lover's Sports
ATESS – (i) Aerospace and Telecommunications Engineering Support Squadron
ATF
- (s) French Southern Territories (ISO 3166 trigram)
- (i) (U.S.) Bureau of Alcohol, Tobacco, Firearms and Explosives (from its previous name, which did not include "Explosives")
ATG – (s) Antigua and Barbuda (ISO 3166 and FIFA trigram)
ATGM – (i) Anti-Tank Guided Missile
ATGW – (i) Anti-Tank Guided Weapon
ATI –
- (i) Allied Telesyn International, Inc.
- (a) Array Technologies Incorporated. (ATI Technologies)
- Air Transport International - American cargo airline
Atisbo – a Local Government Area in Nigeria named for constituent communities (Ago-Are, Tede, Irawo, Sabe, Baasi, Ofiki and Owo)
ATK – (p) Attack
ATL – (p) Atlanta, Georgia, the largest city and capital of Georgia; taken from the IATA code for its airport
ATLAS –
- (a) All-Terrain Lifter Army System
- (p) Assessment Tool for LAnd Systems
ATM –
- (i) Automated Teller Machine
- Asynchronous Transfer Mode
- At The Moment
ATN – (s) Dronning Maud Land (ISO 3166 trigram; merged with AQ in 1983)
ATO
- (i) Air Tasking Order
- Australian Taxation Office
ATP
- (i) Adenosine TriPhosphate
- Allied Tactical Publication
- Ammunition Transfer Point
- Association of Tennis Professionals (cf. ATP Tour, ATP Challenger Tour, ATP Champions Tour)
ATSD – (p) (U.S.) Assistant Secretary of Defense
ATSDR – (i) Agency for Toxic Substances and Disease Registry
AT&T – (i) American Telephone and Telegraph (U.S. company, also known as "Ma Bell")
ATV
- (i) All-terrain vehicle
- Associated Television – former UK TV company
ATWA – (a) Air, Trees, Water, Animals

AU

Au – (s) Gold (Latin Aurum)
AU –
- (i) African Union (was OAU before 2000)
- American University
- (s) Astronomical Unit
- Australia (ISO 3166 diagram)
- Austria (FIPS 10-4 country code)
AUC –
- (i) Ab Urbe Condita / Anno Urbis Conditae (Latin "from the founding of the city" / "in the year since the founding of the city") (of Rome)
- Area Under the Curve (concentration time curve; medicine)
AUD – (s) Australian dollar (ISO 4217 currency code)
AUG – (a) Armee-Universal-Gewehr (German, Army Universal Rifle)
AUS – (s) Australia (ISO 3166 trigram)
AUSCANNZUKUS – (p) Australia, Canada, New Zealand, United Kingdom, United States (security designation)
Auslan – (p) Australian Sign Language
AUT – (s) Austria (ISO 3166 trigram)
AUTL – (i) Army Universal Task List

AV

av – (s) Avar language (ISO 639-1 code)
aV – (s) Attovolt
Av – (i) Aperture value (photographic mode)
AV
- (s) Anguilla (FIPS 10-4 territory code)
- (i) Audio-Visual
- (s) Aviation
ava – (s) Avar language (ISO 639-2 code)
AVA – (i) American Viticultural Area
AVB – (i) Audio Video Bridging
AVCATT-A – (p) (U.S. Army's) Aviation Combed Arms Tactical Trainer-Aviation [Reconfigurable Manned Simulator]
AVDLR – (p) Aviation Depot Level Repair
ave – (s) Avestan language (ISO 639-2 code)
AVGP – (i) Armoured Vehicle, General Purpose
AVI – (i) Audio Video Interleave
AVIM – (p) Aviation Intermediate Maintenance
AVLB – (i) Armoured Vehicle Launched Body
AVM
- (i) Air Vice-Marshal
- (p) Arteriovenous malformation
AVO – (i) Apprehended Violence Order
AVP – (a) Arubaanse Volkspartij
AVP – (i) Association of Volleyball Professionals
AVRE – (i) Armoured Vehicle Royal Engineers
AVTB
- (i) Armoured Vehicle Test Bed
- (p) Aviation Test Bed
AVUM – (p) Aviation Unit Maintenance
AVUS – (a) Automobil-Verkehrs- und Übungsstraße (German, "Automobile Traffic and Training Road"; former auto racing track and current road in Berlin)
AVVO – (a) Acute Vaginal Venereal Outbreak

AW

aW – (s) Attowatt
AW – (s) Aruba (ISO 3166 digram)
AWA – (i) American Wrestling Association
AWACS – (a) Airborne Warning And Control System
AWC – (i) Air Warfare Centre
AWD – many, including All Wheel Drive; see entry
AWE – (i/a) Advanced Warfighting Experiment
AWG – (s) Aruban guilder (ISO 4217 currency code)
AWOL – (a) Absent Without Official Leave / Absent WithOut Leave (military jargon)
AWP – (p) Awaiting Parts (SM&R code)
AWSIM – (p) Air Warfare SIMulation
AWST – (a) Australian Western Standard Time
AWW – (i) Above-Water Warfare

AX

AX – (s) Åland (ISO 3166 digram)
AXP – (p) Ambulance eXchange Point

AY

ay – (s) Aymara language (ISO 639-1 code)
AY – (s) Antarctica (FIPS 10-4 territory code)
AYBABTU – (i) All Your Base Are Belong To Us
aym – (s) Aymara language (ISO 639-2 code)
AYU – (i) As Yet Unknown

AZ

az – (s) Azerbaijani language (ISO 639-1 code)
AZ
- (s) Arizona (postal symbol)
- Azerbaijan (ISO 3166 digram)
- (i) Alkmaar Zaanstreek (Dutch football club)
AZAL – Azerbaijan Airlines
aze – (s) Azerbaijani language (ISO 639-2 code)
AZE – (s) Azerbaijan (ISO 3166 trigram)
AZN – (s) Azerbaijani manat (ISO 4217 currency code)
AZUR – (p) Actions en zone urbaine (French, Urban Operations)

A

Topic: List of acronyms

A0–9

AA

AB

AC

AD

AE

AF

AG

AH

AI

AJ

AK

AL

AM

AN

AO

AP

AQ

AR

AS

AT

AU

AV

AW

AX

AY

AZ