noun the ship which carries the admiral; also, the most considerable ship of a fleet.
2. admiral ·noun a handsome butterfly (pyrameis atalanta) of europe and america. the larva feeds on nettles.
3. admiral ·noun a naval officer of the highest rank; a naval officer of high rank, of which there are different grades. the chief gradations in rank are admiral, vice admiral, and rear admiral. the admiral is the commander in chief of a fleet or of fleets.