moo vs emit

moo is a noun but emit is not a noun.

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

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

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

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

moo (verb)	emit (verb)
make a low noise, characteristic of bovines	expel (gases or odors)
	express audibly; utter sounds (not necessarily words)
	give off, send forth, or discharge; as of light, heat, or radiation, vapor, etc.