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):

sputtering
    n 1: the noise of something spattering or sputtering
         explosively; "he heard a spatter of gunfire" [syn:
         spatter, spattering, splatter, splattering,
         sputter, splutter, sputtering]

Moby Thesaurus II by Grady Ward, 1.0:

24 Moby Thesaurus words for "sputtering":
   beating, clicking, dancing, desultory, drumming, flickering,
   flickery, flicky, fluttering, fluttery, guttering, palpitant,
   pounding, spattering, spluttering, sputtery, staccato, throbbing,
   thrumming, thumping, ticking, unsteady, wavering, wavery