bellower vs roarer

bellower and roarer both are nouns.

Word	Noun	Adjective	Verb	Adverb
bellower	Yes	No	No	No
roarer	Yes	No	No	No

As nouns, bellower and roarer are synonyms defined as:

bellower and roarer: someone who communicates vocally in a very loud voice

Other synonyms of bellower include bawler, screamer, screecher, shouter, yeller.

bellower (noun)	roarer (noun)
someone who communicates vocally in a very loud voice	someone who communicates vocally in a very loud voice