moo vs utter

moo is a noun but utter is not a noun.

Word	Noun	Adjective	Verb	Adverb
moo	Yes	No	Yes	No
utter	No	Yes	Yes	No

As verbs, utter is a hypernym of moo; that is, utter is a word with a broader meaning than moo:

Other hypernyms of moo include emit, let loose, let out.

moo (noun)	utter (noun)
the sound made by a cow or bull

moo (adjective)	utter (adjective)
	complete and absolute
	without qualification; used informally as (often pejorative) intensifiers

moo (verb)	utter (verb)
make a low noise, characteristic of bovines	express in speech
	articulate; either verbally or with a cry, shout, or noise
	express audibly; utter sounds (not necessarily words)
	put into circulation