WordNet (r) 3.0 (2006):

biff
    n 1: (boxing) a blow with the fist; "I gave him a clout on his
         nose" [syn: punch, clout, poke, lick, biff,
         slug]
    v 1: strike, usually with the fist; "The pedestrians pummeled
         the demonstrators" [syn: pummel, pommel, biff]

Moby Thesaurus II by Grady Ward, 1.0:

72 Moby Thesaurus words for "biff":
   bang, bash, bat, beating, belt, blow, bonk, bop, catch, chop, clap,
   clip, clobber, clout, clump, coldcock, crack, cut, dash, deal,
   deal a blow, deck, dig, ding, dint, drub, drubbing, drumming,
   fetch, fetch a blow, fusillade, hit, hit a clip, jab, knock,
   knock cold, knock down, knock out, let have it, lick, nail, paste,
   pelt, plunk, poke, pound, punch, rap, slam, slog, slosh, slug,
   smack, smash, smite, snap, soak, sock, strike, strike at, stroke,
   swat, swing, swipe, tattoo, thump, thwack, wallop, whack, wham,
   whop, yerk



The Jargon File (version 4.4.7, 29 Dec 2003):

biff
 /bif/, vt.

    [now rare] To notify someone of incoming mail. From the BSD utility biff(1)
    , which was in turn named after a friendly dog who used to chase frisbees
    in the halls at UCB while 4.2BSD was in development. There was a legend
    that it had a habit of barking whenever the mailman came, but the author of
    biff says this is not true. No relation to B1FF.


The Free On-line Dictionary of Computing (30 December 2018):

biff

   /bif/ To notify someone of incoming mail.  From the BSD
   utility "biff(1)", which was in turn named after a friendly
   golden Labrador who used to chase frisbees in the halls at UCB
   while 4.2BSD was in development (it had a well-known habit
   of barking whenever the mailman came).  No relation to BIFF.

   [Jargon File]


The Free On-line Dictionary of Computing (30 December 2018):

BIFF
B1FF

   /bif/ (Or "B1FF", from Usenet) The most famous pseudo, and
   the prototypical newbie.  Articles from BIFF are
   characterised by all uppercase letters sprinkled liberally
   with bangs, typos, "cute" misspellings (EVRY BUDY LUVS GOOD
   OLD BIFF CUZ HE'S A K00L DOOD AN HE RITES REEL AWESUM THINGZ
   IN CAPITULL LETTRS LIKE THIS!!!), use (and often misuse) of
   fragments of chat abbreviations, a long sig block
   (sometimes even a doubled sig), and unbounded naivete.  BIFF
   posts articles using his elder brother's VIC-20.  BIFF's
   location is a mystery, as his articles appear to come from a
   variety of sites.  However, BITNET seems to be the most
   frequent origin.  The theory that BIFF is a denizen of BITNET
   is supported by BIFF's (unfortunately invalid) electronic
   mail address: .

   [1993: Now It Can Be Told!  My spies inform me that BIFF was
   originally created by Joe Talmadge , also the
   author of the infamous and much-plagiarised "Flamer's Bible".
   The BIFF filter he wrote was later passed to Richard Sexton,
   who posted BIFFisms much more widely.  Versions have since
   been posted for the amusement of the net at large. - ESR]

   [Jargon File]

   (1997-09-22)