howler vs joke

howler and joke both are nouns.

Word	Noun	Adjective	Verb	Adverb
howler	Yes	No	No	No
joke	Yes	No	Yes	No

As nouns, joke is a hypernym of howler; that is, joke is a word with a broader meaning than howler:

Other hypernyms of howler include gag, jape, jest, laugh.

howler (noun)	joke (noun)
a glaring blunder	a ludicrous or grotesque act done for fun and amusement
monkey of tropical South American forests having a loud howling cry	activity characterized by good humor
a joke that seems extremely funny	a triviality not to be taken seriously
	a humorous anecdote or remark intended to provoke laughter

howler (verb)	joke (verb)
	act in a funny or teasing way
	tell a joke; speak humorously