crier vs roarer

crier and roarer both are nouns.

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

As nouns, roarer is a hypernym of crier; that is, roarer is a word with a broader meaning than crier:

Other hypernyms of crier include hawker, packman, peddler, pedlar, pitchman, bawler, bellower, screamer, screecher, shouter, yeller.

crier (noun)	roarer (noun)
(formerly) an official who made public announcements	someone who communicates vocally in a very loud voice
a person who weeps
a peddler who shouts to advertise the goods he sells