Learn how to say Tailfin correctly in English with this tutorial pronunciation video.
Oxford dictionary definition of the word tail fin:
1 Zoology a fin at the posterior extremity of a fish’s body, typically continuous with the tail. Also called caudal fin.
2 Aeronautics a projecting vertical surface on the tail of an aircraft, providing stability and typically housing the rudder.
3an upswept projection on each rear corner of a car, popular in the 1950s.