n A naval officer of high rank, immediately below Admiral of the Fleet; the commander of a fleet or squadron.
n A flag officer in the United States Navy or United States Coast Guard|Coast Guard of a grade superior to vice admiral and junior to admiral of the fleet (when that grade is used). An admiral is equal in grade or rank to a four star general.
n (zoological) Any of various nymphalid butterflies of Europe and America, especially a red admiral or white admiral.