wail vs holler

wail and holler both are nouns.

Word	Noun	Adjective	Verb	Adverb
wail	Yes	No	Yes	No
holler	Yes	No	Yes	No

As verbs, holler is a hypernym of wail; that is, holler is a word with a broader meaning than wail:

Other hypernyms of wail include call, cry, hollo, scream, shout, shout out, squall, yell.

wail (noun)	holler (noun)
a cry of sorrow and grief	a very loud utterance (like the sound of an animal)
	a small valley between mountains