\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.