roughneck vs ruffian

roughneck and ruffian both are nouns.

Word	Noun	Adjective	Verb	Adverb
roughneck	Yes	No	No	No
ruffian	Yes	No	No	No

As nouns, roughneck and ruffian are synonyms defined as:

Other synonyms of roughneck include bully, hooligan, rowdy, tough, yob, yobbo, yobo.

roughneck (noun)	ruffian (noun)
a cruel and brutal fellow	a cruel and brutal fellow