The Collaborative International Dictionary of English v.0.48:

Sputter \Sput"ter\, v. t.
   To spit out hastily by quick, successive efforts, with a
   spluttering sound; to utter hastily and confusedly, without
   control over the organs of speech.
   [1913 Webster]

         In the midst of caresses, and without the least
         pretended incitement, to sputter out the basest
         accusations.                             --Swift.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Sputter \Sput"ter\, n.
   Moist matter thrown out in small detached particles; also,
   confused and hasty speech.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Sputter \Sput"ter\ (sp[u^]t"t[~e]r), v. i. [imp. & p. p.
   Sputtered (-t[~e]rd); p. pr. & vb. n. Sputtering.] [From
   the root of spout or spit to eject from the mouth. Cf.
   Splutter.]
   1. To spit, or to emit saliva from the mouth in small,
      scattered portions, as in rapid speaking.
      [1913 Webster]

   2. To utter words hastily and indistinctly; to speak so
      rapidly as to emit saliva.
      [1913 Webster]

            They could neither of them speak their rage, and so
            fell a sputtering at one another, like two roasting
            apples.                               --Congreve.
      [1913 Webster]

   3. To throw out anything, as little jets of steam, with a
      noise like that made by one sputtering.
      [1913 Webster]

            Like the green wood . . . sputtering in the flame.
                                                  --Dryden.
      [1913 Webster]

WordNet (r) 3.0 (2006):

sputter
    n 1: the noise of something spattering or sputtering
         explosively; "he heard a spatter of gunfire" [syn:
         spatter, spattering, splatter, splattering,
         sputter, splutter, sputtering]
    2: an utterance (of words) with spitting sounds (as in rage)
       [syn: sputter, splutter]
    v 1: make an explosive sound; "sputtering engines"
    2: cause to undergo a process in which atoms are removed; "The
       solar wind protons must sputter away the surface atoms of the
       dust"
    3: climb awkwardly, as if by scrambling [syn: clamber,
       scramble, shin, shinny, skin, struggle, sputter]
    4: utter with a spitting sound, as if in a rage [syn: sputter,
       splutter]
    5: spit up in an explosive manner [syn: splutter, sputter,
       spit out]

Moby Thesaurus II by Grady Ward, 1.0:

165 Moby Thesaurus words for "sputter":
   assibilate, assibilation, barrage, beat, beat a ruffle,
   beat a tattoo, beating, bicker, blubber, bluff, bluster,
   bluster and bluff, blustering, boastfulness, bounce, brag, bravado,
   bully, bullying, bustle, buzz, crackle, dance, drone, drum,
   drum music, drumbeat, drumfire, drumming, effervesce,
   effervescence, effervescing, ejaculate, eject, fanfaronade, fizz,
   fizzle, fizzling, flap, flick, flicker, flip, flit, flitter, flop,
   flurry, fluster, flutter, frication, frictional rustling, fuss,
   gabble, gasconade, gibber, go pitapat, gutter, heckle, hector,
   hectoring, hiss, hissing, hush, hushing, intimidate, intimidation,
   jabber, lisp, maunder, mouth, mumble, murmur, mutter,
   out-herod Herod, palpitate, palpitation, paradiddle, patter,
   pitapat, pitter-patter, pop, pound, pounding, pulsate, pulsation,
   pulse, quiver, rage, rant, rat-a-tat, rat-tat, rat-tat-tat,
   rataplan, rattattoo, rave, rhonchus, rip out, rodomontade, roister,
   roll, rollick, rub-a-dub, ruff, ruffle, shake, shush, shushing,
   sibilance, sibilate, sibilation, side, siffle, sigmatism, siss,
   sissing, sizz, sizzle, sizzling, slang, slat, sneeze, sneezing,
   sniff, sniffle, snore, snort, snuff, snuffle, sob, sound a tattoo,
   spatter, speak incoherently, spit, splatter, splutter, squash,
   squelch, squish, staccato, sternutation, susurrate, swagger,
   swashbuckle, swashbucklery, swish, tat-tat, tattoo, throb,
   throbbing, throw out, thrum, thump, thumping, tom-tom, vapor, wave,
   waver, wheeze, whish, whisper, whistle, whistling, white noise,
   whiz, whoosh, zip