role player vs ringer

role player and ringer both are nouns.

Word	Noun	Adjective	Verb	Adverb
role player	Yes	No	No	No
ringer	Yes	No	No	No

As nouns, ringer is a hyponym of role player; that is, ringer is a word with a more specific, narrower meaning than role player:

Other hyponyms of role player include name dropper.

role player (noun)	ringer (noun)
a theatrical performer	(horseshoes) the successful throw of a horseshoe or quoit so as to encircle a stake or peg
a person who makes deceitful pretenses	a contestant entered in a competition under false pretenses
	a person who is almost identical to another
	a person who rings church bells (as for summoning the congregation)