Admiral \Ad"mi*ral\, n. [OE. amiral, admiral, OF. amiral, ultimately fr. Ar. am[=i]r-al-bahr commander of the sea; Ar. am[=i]r is commander, al is the Ar. article, and am[=i]r-al, heard in different titles, was taken as one word. Early forms of the word show confusion with L. admirabilis admirable, fr. admirari to admire. It is said to have been introduced into Europe by the Genoese or Venetians, in the 12th or 13th century. Cf. Ameer, Emir.]

1. 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.

2. The ship which carries the admiral; also, the most considerable ship of a fleet.

Like some mighty admiral, dark and terrible, bearing down upon his antagonist with all his canvas straining to the wind, and all his thunders roaring from his broadsides. --E. Everett.

3. (Zo["o]l.) A handsome butterfly (Pyrameis Atalanta) of Europe and America. The larva feeds on nettles.

Admiral shell (Zo["o]l.), the popular name of an ornamental cone shell (Conus admiralis).

Lord High Admiral, a great officer of state, who (when this rare dignity is conferred) is at the head of the naval administration of Great Britain.

Source: Webster's Revised Unabridged Dictionary (1913)