From Longman Dictionary of Contemporary Englishbiffbiff1 /bɪf/ verb 1 [transitive] old-fashioned informalHIT 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→ See Verb tablebiffbiff2 noun [countable] informal an embarrassing mistakeOrigin biff (1800-1900) Probably from the sound of hitting