Ratter

n.	1.	One who, or that which, rats, as one who deserts his party.
	2.	Anything which catches rats; esp., a dog trained to catch rats; a rat terrier. See Terrier.

Noun	1.	ratter - a disloyal person who betrays or deserts his cause or religion or political party or friend etc. Synonyms: apostate, deserter, turncoat, recreant, renegade
	2.	ratter - any of several breeds of terrier developed to catch rats Synonyms: rat terrier

apostate, betray, blackleg, denounce, deserter, give away, grass, quitter, rat, recreant, renegade, scab, shit, shop, snitch, stag, tell on, turncoat