1. A membranous appendage extending from the body of a fish or other aquatic animal, used for propelling, steering, or balancing the body in the water.
2. Something resembling a fin in shape or function, as:
3. A fixed or movable airfoil used to stabilize an aircraft, missile, or projectile in flight.
4. A thin, usually curved projection attached to the rear bottom of a surfboard for stability.
5. A projecting vane used for cooling, as on a radiator or an engine cylinder.
6. See tail fin.
7. See flipper.
8. Slang A five-dollar bill.
1. To emerge with the fins above water.
2. To swim, as a fish.
3. To lash the water with the fins. Used of a dying whale.
1. To equip with fins.
Sentence Example with fin
And I shall know that I must die, at sea most likely, cease crawling of myself to be all a-crawl with the corruption of the sea; to be fed upon, to be carrion, to yield up all the strength and movement of my muscles that it may become strength and movement in fin and scale and the guts of fishes.