A noun used to describe sexual
intercourse - is usually used by someone who has an
obsession with sharks or sea creatures.
Can be used interchangeably with the word
ass.
Kyle: I was gettin' some fin last night - it was hot!
Morality Preacher: Whoa, whoa little pup - you're not
even a
shark yet. You should wait a few years before tappin' that fin ;)
Kyle:
Yay Morals!