Definition of FIN

  1. (verb)equip (a car) with fins
  2. (verb)propel oneself through the water in a finning motion
  3. (verb)show the fins above the water while swimming
  4. (noun)the cardinal number that is the sum of four and one
  5. (noun)one of a pair of decorations projecting above the rear fenders of an automobile
  6. (noun)one of a set of parallel slats in a door or window to admit air and reject rain
  7. (noun)a shoe for swimming; the paddle-like front is an aid in swimming (especially underwater)
  8. (noun)a stabilizer on a ship that resembles the fin of a fish
  9. (noun)organ of locomotion and balance in fishes and some other aquatic animals