WordNet (r) 3.0 (2006):

foul up
    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]

Moby Thesaurus II by Grady Ward, 1.0:

100 Moby Thesaurus words for "foul up":
   anarchy, ball up, bitch, bitch up, bloomer, blooper, blow, bobble,
   bollix, bollix up, bonehead into it, bonehead play, boner, boo-boo,
   boob stunt, boot, bugger, bugger up, butterfingers, chaos, clumsy,
   complicate, confound, confuse, confusion, cook, crab, cramp, crimp,
   drop a brick, drop the ball, dub, duff, duffer, dumb trick,
   embrangle, entangle, fabulous formless darkness, flub, fluff,
   fool mistake, foozle, foozler, fumble, fumble-fist, garble, goof,
   goof up, goofball, goofer, gum, gum up, hash up, hassle, hick,
   howler, implicate, involve, jumble, knot, license, louse up,
   louse-up, lummox, lump, mess up, misrule, mix up, mix-up, morass,
   muck up, muck-up, muddle, muff, muffer, perplex, pi,
   play hell with, play hob with, pratfall, pull a boner, queer,
   ramify, ravel, riffle, rube, scramble, screamer, screw up,
   screw-up, shuffle, sink, slob, snafu, snarl, snarl up, stumblebum,
   stumblebunny, tangle, tumble