Cohort

A cohort is generally a group or company of people.

In military terms a cohort is any group of soldiers or warriors. In an ancient Roman legion, it was one of the ten divisions, numbering from 300 to 600 troops.

A cohort is also a group used in a study in which all the members of the group have a common characteristic, such as age. This concept is used often in medical research.

Individually a cohort is a companion or associate; in crime an accomplice, one who is an abettor.

In Biology, a cohort is an individual in a population of the same species.