fraud vs ringer

fraud and ringer both are nouns.

Word	Noun	Adjective	Verb	Adverb
fraud	Yes	No	No	No
ringer	Yes	No	No	No

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

Other hyponyms of fraud include name dropper.

fraud (noun)	ringer (noun)
intentional deception resulting in injury to another person	(horseshoes) the successful throw of a horseshoe or quoit so as to encircle a stake or peg
something intended to deceive; deliberate trickery intended to gain an advantage	a contestant entered in a competition under false pretenses
the act of swindling by some fraudulent scheme	a person who is almost identical to another
a person who makes deceitful pretenses	a person who rings church bells (as for summoning the congregation)