holloa vs holla

holloa and holla both are nouns.

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

As nouns, holloa and holla are synonyms defined as:

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

holloa (noun)	holla (noun)
a very loud utterance (like the sound of an animal)	a very loud utterance (like the sound of an animal)