belly laugh vs howler

belly laugh and howler both are nouns.

Word	Noun	Adjective	Verb	Adverb
belly laugh	Yes	No	No	No
howler	Yes	No	No	No

As nouns, belly laugh and howler are synonyms defined as:

Other synonyms of belly laugh include riot, scream, sidesplitter, thigh-slapper, wow.

belly laugh (noun)	howler (noun)
a joke that seems extremely funny	a glaring blunder
a burst of deep loud hearty laughter	monkey of tropical South American forests having a loud howling cry
	a joke that seems extremely funny