The Collaborative International Dictionary of English v.0.48:

fizzle \fiz"zle\ (f[i^]z"z'l), v. i. [imp. & p. p. fizzled
   (f[i^]z"z'ld); p. pr. & vb. n. fizzling (f[i^]z"zl[i^]ng).]
   [See Fizz.]
   1. To make a hissing sound.
      [1913 Webster]

            It is the easiest thing, sir, to be done,
            As plain as fizzling.                 --B. Jonson.
      [1913 Webster]

   2. To make a ridiculous failure in an undertaking, especially
      after a good start; to achieve nothing. [Colloq. or Low]
      [1913 Webster +PJC]

            A four-day rally in stocks fizzled yesterday amid
            renewed fears that strong economic growth may prompt
            the Federal Reserve to raise interest rates.
                                                  --Sharon R.
                                                  King (N. Y.
                                                  Times, May 6,
                                                  1998).
      [PJC]

   To fizzle out, to burn with a hissing noise and then go
      out, like wet gunpowder; hence: to fail completely and
      ridiculously; to prove a failure. [Colloq.]
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

fizzle \fiz"zle\, n.
   A failure or abortive effort; a fiasco. [Colloq.]
   [1913 Webster]

WordNet (r) 3.0 (2006):

fizzle
    n 1: a fricative sound (especially as an expression of
         disapproval); "the performers could not be heard over the
         hissing of the audience" [syn: hiss, hissing,
         hushing, fizzle, sibilation]
    2: a complete failure; "the play was a dismal flop" [syn:
       flop, bust, fizzle]
    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:

156 Moby Thesaurus words for "fizzle":
   abort, assibilate, assibilation, bafflement, balk,
   be disappointing, betrayed hope, blasted expectation,
   blighted hope, blow, blow up, blubber, boil, boil over, boiling,
   bomb, bubble, bubble over, bubble up, bubbliness, bubbling, buffet,
   burble, burn out, bust, buzz, carbonation, cave in, collapse,
   come short, come to grief, come to naught, come to nothing,
   comedown, cruel disappointment, dash, dashed hope, defeat, die,
   die away, die out, disappointment, discomfiture, disillusionment,
   dissatisfaction, dull thud, ebullience, ebulliency, ebullition,
   effervesce, effervescence, effervescency, effervescing, expire,
   explode, fail, fail miserably, failure, fall short, fall through,
   fallen countenance, ferment, fermentation, fiasco, fizz, fizz out,
   fizzle out, fizzling, flame out, flat failure, flop, floperoo,
   foaming, foiling, forlorn hope, frication, frictional rustling,
   frost, frothiness, frothing, frustration, get nowhere, go out,
   go phut, go wrong, guggle, gurgle, hang up, hiss, hissing,
   hope deferred, hush, hushing, lemon, letdown, lisp, mirage,
   miscarry, misfire, not hack it, not make it, peter out, plop,
   poop out, rhonchus, seethe, setback, shush, shushing, sibilance,
   sibilate, sibilation, siffle, sigmatism, simmer, siss, sissing,
   sizz, sizzle, sizzling, sneeze, sneezing, sniff, sniffle, snore,
   snort, snuff, snuffle, sore disappointment, sparkle, spit,
   splutter, spumescence, sputter, squash, squelch, squish,
   sternutation, stertor, swish, tantalization, tease, total loss,
   turkey, turn sour, washout, wheeze, whish, whisper, whistle,
   whistling, white noise, whiz, whoosh, work, zip