To throw something with vigour, informal. Cape Breton english
You better not biff that snowball b'y
I biffed that stick right at his face
An easier way of pronouncing the acronym B.F. (Best Friends) or B.F.F. (Best Friends Forever)
Cody: Are we BFFs?
Amber: dude we're BIFFS
A romantic character in a novel or movie.
The guy in "The Notebook" was a Biff.