mug [E16th] A mug was first of all a measure of salt, then a large earthenware vessel or bowl [E16th] before becoming the familiar drinking vessel in the mid 17th century. In the 18th century drinking mugs commonly represented a grotesque human face. This may be the origin of mug [E18th] in the sense ‘a face’, which in turn probably gave rise to mug [M19th] as an insult for a stupid or gullible person, from their blank or unintelligent expression. In 19th-century slang mug was particularly a term for someone who has been duped by a card sharp or confidence trickster—this is behind a mug’s game [E20th]. People were robbed and attacked in public places before the 1860s, but before then the words mug and mugger would not have been used. They go back to the ‘face’ sense: to mug was originally a boxing term meaning ‘to punch an opponent in the face’ or ‘a blow to the face’. Muggins [E18th] is perhaps related to the ‘fool’ or ‘dupe’ senses, but the exact relationship is not clear.