rat
noun
°Any of about 56 different species of small, omnivorous rodents belonging to the genus Rattus.
°A term indiscriminately applied to numerous members of several rodent families (e.g. voles and mice) having bodies longer than about 12 cm, or 5 inches.
verb
°(usually with “on” or “out”) to betray someone and tell their secret to an authority or an enemy; to turn someone in, bewray.
°(of a dog, etc.) To kill rats.
synonyms: traitor, stool pigeon, tell, finger more» , bewray