WordNet (r) 3.0 (2006):

fizzle out
    v 1: end weakly; "The music just petered out--there was no
         proper ending" [syn: taper off, peter out, fizzle
         out, fizzle]

Moby Thesaurus II by Grady Ward, 1.0:

66 Moby Thesaurus words for "fizzle out":
   be disappointing, be unproductive, blow up, break, break down,
   burn out, cave in, collapse, come apart, come short,
   come to naught, come to nothing, come unstuck, conk out, crumble,
   decline, die, die away, die out, disintegrate, droop, drop,
   explode, fade, fail, fail miserably, faint, fall down, fall flat,
   fall short, fall through, fizz out, fizzle, flag, flame out,
   get bogged down, get hung up, get mired, get nowhere, give out,
   give way, go downhill, go out, go phut, go soft, go to pieces,
   go wrong, hang fire, hang up, hit the skids, languish, lie fallow,
   misfire, not hack it, not make it, peg out, peter out, pine,
   poop out, sink, turn sour, weaken, wear away, wear thin, wilt,
   yield