quitter vs ratter

quitter and ratter both are nouns.

Word	Noun	Adjective	Verb	Adverb
quitter	Yes	No	No	No
ratter	Yes	No	No	No

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

quitter: a person who gives up too easily
ratter: a disloyal person who betrays or deserts his cause or religion or political party or friend etc.

Other hyponyms of quitter include abdicator, dropout, apostate, deserter, recreant, renegade, turncoat.

quitter (noun)	ratter (noun)
a person who gives up too easily	any of several breeds of terrier developed to catch rats
	a disloyal person who betrays or deserts his cause or religion or political party or friend etc.