stutter vs speak

stutter is a noun but speak is not a noun.

Word	Noun	Adjective	Verb	Adverb
stutter	Yes	No	Yes	No
speak	No	No	Yes	No

As verbs, speak is a hypernym of stutter; that is, speak is a word with a broader meaning than stutter:

Other hypernyms of stutter include mouth, talk, utter, verbalise, verbalize.

stutter (noun)	speak (noun)
a speech disorder involving hesitations and involuntary repetitions of certain sounds

stutter (verb)	speak (verb)
speak haltingly	express in speech
	exchange thoughts; talk with
	use language
	give a speech to
	make a characteristic or natural sound