/mug/ , n. , v. , mugged, mugging .
n.
1. a drinking cup, usually cylindrical in shape, having a handle, and often of a heavy substance, as earthenware.
2. the quantity it holds.
3. Slang.
a. the face.
b. the mouth.
c. an exaggerated facial expression; grimace, as in acting.
d. a thug, ruffian, or other criminal.
4. Brit. Slang. a gullible person; dupe; fool.
v.t.
5. to assault or menace, esp. with the intention of robbery.
6. Slang. to photograph (a person), esp. in compliance with an official or legal requirement.
v.i.
7. Slang. to grimace; exaggerate a facial expression, as in acting.
[ 1560-70; prob. mugg, Norw, Dan mugge drinking cup; sense "face" appar. transferred from cups adorned with grotesque faces; sense "to assault" from earlier pugilistic slang "to strike in the face, fight" ]