What is the meaning of Commodore?

A naval officer holding a rank between captain and rear admiral.

A (temporary) commander over a collection of ships who is not an admiral.

The leading ship in a fleet of merchantmen.

The president of a yacht club.

A yacht-club president's vessel in a regatta.

Ellipsis of commodore admiral.

A rear admiral (lower half).

Any of various nymphalid butterflies of the Asian genus Parasarpa.

commodore, a naval military rank between captain (capitaine de vaisseau or capitaine de croiseur) and rear admiral (contre-amiral)

Source: wiktionary.org