roarer vs screamer

roarer and screamer both are nouns.

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

As nouns, roarer and screamer are synonyms defined as:

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

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

roarer (noun)	screamer (noun)
someone who communicates vocally in a very loud voice	a very hard hit ball
	gooselike aquatic bird of South America having a harsh trumpeting call
	a sensational newspaper headline
	someone who communicates vocally in a very loud voice