fin

1. (noun) One of the appendages of a fish, used to propel itself and to manoeuvre/maneuver. 2. (noun) A similar appendage of a cetacean or other marine animal. 3. (noun) A thin, rigid component of an aircraft, extending from the fuselage and used to stabilise and steer the aircraft. 4. (noun) A similar structure on the tail of a bomb, used to help keep it on course. 5. (noun) A hairstyle, resembling the fin of a fish, in which the hair is combed and set into a vertical ridge along the top of the head from about the crown to the forehead. 6. (noun) A device worn by divers and swimmers on their feet. 7. (noun) An extending part on a surface of a radiator, engine, heatsink, etc., used to facilitate cooling. 8. (noun) A sharp raised edge (generally in concrete) capable of damaging a roof membrane or vapor retarder. 9. (verb) To cut the fins from a fish, shark, etc. 10. (verb) (Of a fish) to swim with the dorsal fin above the surface of the water. 11. (verb) To swim in the manner of a fish. 12. (verb) To provide (a motor vehicle etc) with fins.