The Collaborative International Dictionary of English v.0.48:

Splutter \Splut"ter\ (spl[u^]t"t[~e]r), v. i. [imp. & p. p.
   Spluttered (-t[~e]rd); p. pr. & vb. n. Spluttering.]
   [Prov. E. splutter, eqivalent to sputter. Cf. Sputter.]
   To speak hastily and confusedly; to sputter. [Colloq.]
   --Carleton.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Splutter \Splut"ter\, n.
   A confused noise, as of hasty speaking. [Colloq.]
   [1913 Webster]

WordNet (r) 3.0 (2006):

splutter
    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: utter with a spitting sound, as if in a rage [syn:
         sputter, splutter]
    2: spit up in an explosive manner [syn: splutter, sputter,
       spit out]

Moby Thesaurus II by Grady Ward, 1.0:

161 Moby Thesaurus words for "splutter":
   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, dance, drone, drum, drum music,
   drumbeat, drumfire, drumming, effervesce, effervescence,
   effervescing, fanfaronade, fizz, fizzle, fizzling, flap, flick,
   flicker, flip, flit, flitter, flop, flurry, fluster, flutter,
   frication, frictional rustling, fuss, gabble, gasconade, gibber,
   go pitapat, gutter, 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, 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, sputter, squash, squelch, squish, staccato, sternutation,
   stertor, storm, susurrate, swagger, swashbuckle, swashbucklery,
   swish, tat-tat, tattoo, throb, throbbing, thrum, thump, thumping,
   tom-tom, vapor, wave, waver, wheeze, whish, whisper, whistle,
   whistling, white noise, whiz, whoosh, zip