ratastoolie
Derogatory term used by one or more really "stewed" law-breakers who got caught and jailed; da term would refer to a former "seasoned" partner-in-crime associate who turned state's evidence in order to avoid a lengthy stint in da slammer, as well.
I always try to just mind my own business, treat fellow humans respectfully, obey da law, and avoid "questionable" company, so hopefully I'll never get into a situation where anybody will feel like referring to me as a "ratastoolie".