mugging (n.)

"to beat up," 1818, originally "to strike the face" (in pugilism), from mug (n.2) "face." The general meaning "attack" is attested by 1846, and "attack to rob" by 1864. Perhaps influenced by thieves' slang mug "dupe, fool, sucker" (1851). Related: Mugged; mugging.

"make exaggerated facial expressions," 1855, originally theatrical slang, from mug (n.2) "face." Related: Mugged; mugging.