: a fin at the back end of a fish, whale, etc.
: a decorative part on the back of a car that is shaped like a fish's fin
What made you want to look up tail fin? Please tell us where you read or heard it (including the quote, if possible).
Take our visual vocab quiz
A quick quiz about stuff worth knowing
The commonly misspelled words quiz
The Vocab Quiz Game for iPhone & iPad
"Incredibly fun and addictive. And informative!" User Review, iTunes