A slaphead is usually a guy who is so naturally bald he makes most
bald people look positively hirsuit, but really it can be any guy who is definitely bald or going bald. A slaphead is so obviously bald that you just wish it was acceptable to point out the patently obvious by slapping them 5 or 6 times in rapid succession on their bald
shiny head. The term slaphead was actually introduced in the comedy of
Benny Hill, a world famous British comedian (deceased). Benny always used a sketch where a small bald man would do something a little annoying to Benny Hill and benny would slap the guy a few times on his bald head.