bellowing vs hollo

bellowing and hollo both are nouns.

Word	Noun	Adjective	Verb	Adverb
bellowing	Yes	No	No	No
hollo	Yes	No	Yes	No

As nouns, bellowing and hollo are synonyms defined as:

bellowing and hollo: a very loud utterance (like the sound of an animal)

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

bellowing (noun)	hollo (noun)
a very loud utterance (like the sound of an animal)	a very loud utterance (like the sound of an animal)

bellowing (verb)	hollo (verb)
	utter a sudden loud cry
	cry hollo
	encourage somebody by crying hollo