utterance vs howl

utterance and howl both are nouns.

Word	Noun	Adjective	Verb	Adverb
utterance	Yes	No	No	No
howl	Yes	No	Yes	No

As nouns, howl is a hyponym of utterance; that is, howl is a word with a more specific, narrower meaning than utterance:

utterance (noun)	howl (noun)
the use of uttered sounds for auditory communication	a long loud emotional utterance
	a loud sustained noise resembling the cry of a hound
	the long plaintive cry of a hound or a wolf

utterance (verb)	howl (verb)
	laugh unrestrainedly and heartily
	make a loud noise, as of wind, water, or vehicles
	emit long loud cries
	cry loudly, as of animals