bear witness against betray betrayer blab blabber blabberer blabbermouth blackleg blow the whistle canary delator inform against inform on informer narc nark peach peacher rat scab sell out snitch snitch on snitcher spy squeal squealer stool stool pigeon stoolie strikebreaker talebearer tattle tattler tattletale tell on telltale testify against tipster turn informer whistle-blower