____ was a UK equivalent of the US "Kilroy” in 1940s graffiti (4)
I believe the answer is:
chad
(Other definitions for chad that I've seen before include "N.Central African Republic" , "article put out by Punch?" , "Punched paper; African nation" , "Large, shallow lake in north central Africa" , "Small piece that's removed when a hole is punched, in a card say" .)