Prat
Q From Adams Douglas: In some British magazines I have noticed the word prat, which seems in context to mean a fool or stupid person. Is this related to pratfall?
A It is, yes. Prat in this sense means “backside; buttocks”, first recorded in the sixteenth century but of unknown origin. A pratfall is a comedy fall on to the buttocks. The British slang sense dates from the 1960s and means an incompetent, foolish or stupid person. It became popular in the 1980s. It isn’t obscene, but it’s a sharp expression of criticism or abuse.