What is the meaning of Captain?

A chief or leader.

The person lawfully in command of a ship or other vessel.

An army officer with a rank between the most senior grade of lieutenant and major.

A naval officer with a rank between commander and commodore.

A commissioned officer in the United States Navy, Coast Guard, NOAA Corps, or PHS Corps of a grade superior to a commander and junior to a rear admiral (lower half). A captain is equal in grade or rank to a United States Army, Marine Corps, or Air Force colonel.

One of the athletes on a sports team who is designated to make decisions, and is allowed to speak for his team with a referee or official.

The leader of a group of workers.

The head boy of a school.

A maître d', a headwaiter.

An honorific title given to a prominent person. See colonel.

To act as captain

To exercise command of a ship, aircraft or sports team.

Source: wiktionary.org