holloa vs hollering

holloa and hollering both are nouns.

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

As nouns, holloa and hollering are synonyms defined as:

holloa and hollering: a very loud utterance (like the sound of an animal)

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

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