Yes, sputter is a Scrabble word!

Verb

1. Make an explosive sound

2. Cause to undergo a process in which atoms are removed

3. Climb awkwardly, as if by scrambling

4. Utter with a spitting sound, as if in a rage

5. Spit up in an explosive manner

Noun

1. The noise of something spattering or sputtering explosively

2. An utterance (of words) with spitting sounds (as in rage)