WordNet (r) 3.0 (2006):

set on
    v 1: attack someone physically or emotionally; "The mugger
         assaulted the woman"; "Nightmares assailed him regularly"
         [syn: assail, assault, set on, attack]

Moby Thesaurus II by Grady Ward, 1.0:

118 Moby Thesaurus words for "set on":
   abet, aching for, aggravate, agitate, alienate, ambush, arouse,
   assail, assault, attack, bed on, bent on, blitz, blow the coals,
   bottom on, build on, bushwhack, come at, come between,
   come down on, crack down on, crazy to, dead set on, decided upon,
   descend on, descend upon, desirous of, determined upon, disaffect,
   disunite, divide, dying for, dying to, estrange, excite, fain of,
   fall on, fall upon, fan, fan the flame, feed the fire, ferment,
   fire, fixed upon, foment, fond of, found on, gang up on, go at,
   go for, ground on, harry, have at, heat, heat up, hell-bent on,
   hit, hit like lightning, impassion, incense, incite,
   inclined toward, inflame, instigate, intent upon, irritate,
   itching for, jump, keen on, land on, lay at, lay hands on,
   lay into, leaning toward, light into, light the fuse, mad on,
   make trouble, mug, nettle, partial to, pique, pit against,
   pitch into, pounce upon, pound, provoke, put up to, raise, rally,
   resolved upon, sail into, separate, set, set against, set at odds,
   set at variance, set upon, settled upon, sic on, sot on,
   sow dissension, spoiling for, stir the embers, stir up,
   stir up trouble, strike, surprise, swoop down on,
   take the offensive, tickle, undergird, underlie, wade into, whet,
   whip up, wild to, work up