yeller vs roarer

yeller and roarer both are nouns.

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

As nouns, yeller and roarer are synonyms defined as:

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

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

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