Fin

(noun) the cardinal number that is the sum of four and one. Synonyms: five, 5, V, cinque, quint, quintet, fivesome, quintuplet, pentad, fin, Phoebe, Little Phoebe.

(noun) one of a pair of decorations projecting above the rear fenders of an automobile. Synonyms: tail fin, tailfin, fin.

(noun) one of a set of parallel slats in a door or window to admit air and reject rain. Synonyms: louver, louvre, fin.

(noun) a shoe for swimming; the paddle-like front is an aid in swimming (especially underwater). Synonyms: flipper, fin.

(noun) a stabilizer on a ship that resembles the fin of a fish. Synonyms: fin.

(noun) organ of locomotion and balance in fishes and some other aquatic animals. Synonyms: fin.

(verb) equip (a car) with fins. Synonyms: fin.

(verb) propel oneself through the water in a finning motion. Synonyms: fin.

(verb) show the fins above the water while swimming. Synonyms: fin, break water. Example: "The sharks were finning near the surface."