The Collaborative International Dictionary of English v.0.48:

Mugging \Mug"ging\, n. [p. pr. & vb. n. from mug, v.]
   A robbery; a taking of property by threatening (or
   performing) violence on the person who is robbed. See mug,
   v.

   Syn: robbery, holdup, stickup
        [PJC + WordNet 1.5]

WordNet (r) 3.0 (2006):

mugging
    n 1: assault with intent to rob

Moby Thesaurus II by Grady Ward, 1.0:

64 Moby Thesaurus words for "mugging":
   aggravated assault, aggression, amphibious attack, armed assault,
   armed robbery, asportation, assailing, assailment, assault,
   assault and robbery, attack, banditry, bank robbery, banzai attack,
   blitz, blitzkrieg, breakthrough, cattle lifting, cattle stealing,
   charge, counterattack, counteroffensive, coup de main,
   crippling attack, dead set at, descent on, diversion,
   diversionary attack, drive, extortion, flank attack,
   frontal attack, gas attack, head-on attack, heist, highway robbery,
   hijacking, holdup, infiltration, lightning attack, lightning war,
   mass attack, megadeath, offense, offensive, onset, onslaught,
   overkill, panzer warfare, pocket picking, purse snatching, push,
   robbery, robbing, run against, run at, rush, sally, shock tactics,
   sortie, stickup, stickup job, strike, unprovoked assault