slap [LME] When slap first came into English it was probably meant to imitate the sound of a blow with the palm of the hand. Slap and tickle, playful sexual activity, dates from the early 20th century. To create the sound of a blow in the theatre or circus, pantomime actors and clowns use a device consisting of two flexible pieces of wood joined together at one end. This is a slapstick [L19th], Since then it has also been the term for comedy based on deliberately clumsy actions and embarrassing events. Slaphead is British slang for a bald man, recorded from the late 1980s.