- The word, “muggin’”, is a reference to mug shots because the person in the picture is staring at the camera and often in an odd manner.
Muggin'
verb; slang
Staring at someone in an odd way
Etymology : Mug is from mug shot. -in' comes from the suffix -ing that denotes that an action is occurring.
Source : Conversation
Last modified: 8 December 2010