A fellow curious about the term mug shot sent us flipping through page after page in our efforts to pin down that term's origin. Everyone knows a mug shot is a photograph of usually a person's head and especially face and that the term also refers specifically to a police photograph of a suspect's face or profile. Although we know the shot part comes from snapshot , focusing on the story behind mug is a bit more difficult. This mug is often used humorously to suggest an ugly, although not displeasing, physiognomy.
Jokers know about mugging for comic effect.
To mug is to pose or make faces, especially to attract attention or for a camera. We don't know if the foolish look of folks mugging inspired the sense of mug that means fool or blockhead , but we do know that our friends across the Atlantic have extended that word's meaning to a particular kind of fool. In British English, a mug is a gullible person, especially the victim of a swindle or fraud. It is also used as a byword for one of the criminal element , such as a punk or thug . No one knows, although one theory has it that mug came to mean face because of the onetime practice of representing faces on the cylindrical drinking cup mug .