holla vs holler

holla and holler both are nouns.

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

As nouns, holla and holler are synonyms defined as:

Other synonyms of holla include bellow, bellowing, hollering, hollo, holloa, roar, roaring, yowl.

holla (noun)	holler (noun)
a very loud utterance (like the sound of an animal)	a very loud utterance (like the sound of an animal)
	a small valley between mountains