howler vs pratfall

howler and pratfall both are nouns.

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

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

Other hypernyms of howler include bloomer, blooper, blunder, boner, boo-boo, botch, bungle, flub, foul-up, fuckup.

howler (noun)	pratfall (noun)
a glaring blunder	an embarrassing mistake
monkey of tropical South American forests having a loud howling cry	a fall onto your buttocks
a joke that seems extremely funny