roarer vs screecher

roarer and screecher both are nouns.

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

As nouns, roarer and screecher are synonyms defined as:

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

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

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