A naval designation that may apply to the senior officer of a group of ships regardless of personal rank, or to a rank between captain (naval) and rear admiral, which may be a wartime-only temporary rank or the lowest level of admiral.
In military use, a commodore may hold the temporary rank in a relatively long-lived post, such as commanding task groups or serving as a chief of staff for a senior officer (e.g., Arleigh Burke in Fast Carrier Forces, Pacific Fleet). Alternatively, it may be used for a single mission, such as "convoy commodore" or "escort commodore".
"Commodore" is also used in some civilian contexts. Tge senior captain of a maritime company that operates multiple ships usually has the courtesy title of commodore. It is also encountered as a leadership title in groups such as yacht clubs.