shouter vs roarer

shouter and roarer both are nouns.

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

As nouns, shouter and roarer are synonyms defined as:

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

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

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