Sarbut means: Sarbut is British regional slang for a police informer - someone who rats to the cops. It's the kind of word you'd hear in tight-knit working-class communities where grassing someone up was. It is informal slang, fine in casual speech but not suited to formal contexts. There is no real cause for parental concern; it is descriptive vocabulary rather than risky behaviour. As a place or proper-name reference it is purely descriptive.