fin

 
Pronunciation: /fɪn/

noun

  • a flattened appendage on various parts of the body of many aquatic vertebrates, including fish and cetaceans, and some invertebrates, used for propelling, steering, and balancing.
  • an underwater swimmer’s flipper.
  • a small flattened projecting surface or attachment on an aircraft, rocket, or car, for providing aerodynamic stability.
  • a flattened projection on a device, used for increasing heat transfer.

verb (fins, finning, finned)

[no object, with adverbial of direction]
  • swim under water by means of flippers: we finned along the side of the wreck

Derivatives

finless

adjective

finned

adjective
[in combination]: long-finned pike

Origin:

Old English finn, fin, of Germanic origin; related to Dutch vin and probably ultimately to Latin pinna 'feather, wing'