splutter vs expectorate

splutter is a noun but expectorate is not a noun.

Word	Noun	Adjective	Verb	Adverb
splutter	Yes	No	Yes	No
expectorate	No	No	Yes	No

As verbs, expectorate is a hypernym of splutter; that is, expectorate is a word with a broader meaning than splutter:

splutter: spit up in an explosive manner
expectorate: discharge (phlegm or sputum) from the lungs and out of the mouth

Other hypernyms of splutter include cough out, cough up, spit out, spit up.

splutter (noun)	expectorate (noun)
an utterance (of words) with spitting sounds (as in rage)
the noise of something spattering or sputtering explosively

splutter (verb)	expectorate (verb)
spit up in an explosive manner	discharge (phlegm or sputum) from the lungs and out of the mouth
utter with a spitting sound, as if in a rage	clear out the chest and lungs