I. biff 1 /bɪf/ BrE AmE verb
[ Date: 1800-1900 ; Origin: Probably from the sound of hitting ]
1 . [transitive] old-fashioned informal to hit someone hard with your ↑ fist SYN thump :
He biffed me on the nose.
2 . [intransitive] informal to fall or hit something when riding a bicycle, ↑ snowboard etc
II. biff 2 BrE AmE noun [countable] informal
an embarrassing mistake