WordNet (r) 3.0 (2006):

flub
    n 1: an embarrassing mistake [syn: blunder, blooper,
         bloomer, bungle, pratfall, foul-up, fuckup,
         flub, botch, boner, boo-boo]
    v 1: make a mess of, destroy or ruin; "I botched the dinner and
         we had to eat out"; "the pianist screwed up the difficult
         passage in the second movement" [syn: botch, bodge,
         bumble, fumble, botch up, muff, blow, flub,
         screw up, ball up, spoil, muck up, bungle,
         fluff, bollix, bollix up, bollocks, bollocks up,
         bobble, mishandle, louse up, foul up, mess up,
         fuck up]

The Free On-line Dictionary of Computing (19 January 2023):

FLUB

    The abstract machine for bootstrapping
   STAGE2.

   [Mentioned in Machine Oriented Higher Level Languages, W. van
   der Poel, N-H 1974, p. 271].

   (1995-03-13)