Noun:
1: quintuplet, cinque, quintet, pentad, fivesome, 5, quint, little phoebe, fin, phoebe, five, v the cardinal number that is the sum of four and one
2: fin, tail fin, tailfin one of a pair of decorations projecting above the rear fenders of an automobile
3: louvre, louver, fin one of a set of parallel slats in a door or window to admit air and reject rain
4: fin, flipper a shoe for swimming; the paddle-like front is an aid in swimming (especially underwater)
5: fin a stabilizer on a ship that resembles the fin of a fish
6: fin organ of locomotion and balance in fishes and some other aquatic animals
Verb:
1: fin equip (a car) with fins
2: fin propel oneself through the water in a finning motion
3: break water, fin show the fins above the water while swimming; "The sharks were finning near the surface"