Etymology: Victorian underworld slang. An abbess (Latin abbatissa, fem. form of abbas, abbot) is the female superior, or Mother Superior, of an abbey or convent of nuns. Since the Elizabethan era, nun has been slang for a prostitute (ref. William Faulkner, "Requiem for a Nun"), and a nunnery referred to a brothel.
Walter Winchell, 1953