WordNet (r) 3.0 (2006):

turn on
    v 1: cause to operate by flipping a switch; "switch on the
         light"; "turn on the stereo" [syn: switch on, turn on]
         [ant: cut, switch off, turn off, turn out]
    2: be contingent on; "The outcomes rides on the results of the
       election"; "Your grade will depends on your homework" [syn:
       depend on, devolve on, depend upon, ride, turn on,
       hinge on, hinge upon]
    3: produce suddenly or automatically; "Turn on the charm"; "turn
       on the waterworks"
    4: become hostile towards; "The dog suddenly turned on the
       mailman"
    5: cause to be agitated, excited, or roused; "The speaker
       charged up the crowd with his inflammatory remarks" [syn:
       agitate, rouse, turn on, charge, commove, excite,
       charge up] [ant: calm, calm down, lull, quiet,
       quieten, still, tranquilize, tranquillise,
       tranquillize]
    6: stimulate sexually; "This movie usually arouses the male
       audience" [syn: arouse, sex, excite, turn on, wind
       up]
    7: get high, stoned, or drugged; "He trips every weekend" [syn:
       trip, trip out, turn on, get off]

Moby Thesaurus II by Grady Ward, 1.0:

170 Moby Thesaurus words for "turn on":
   accrue from, amplify, annoy, arise from, arouse, awake, awaken,
   be based on, be contingent on, be dependent on, be due to,
   be predicated on, blow the coals, blow up, bring up, broach,
   bud from, call forth, call up, charge, christen, come from,
   come out of, depend, depend on, derive from, descend from,
   electrify, emanate from, emerge from, energize, enkindle, enrage,
   ensue from, establish, excite, fan, fan the fire, fan the flame,
   feed the fire, fidget, fire, flame, flip out, float, flow from,
   flutter, follow from, foment, found, freak out on, frenzy,
   galvanize, generate, germinate from, get high on, glow, go pitapat,
   grow from, grow out of, hang, hang on, have the fidgets,
   have the shakes, heat, heave, hinge, hinge on, impassion,
   inaugurate, incense, incite, induct, inflame, infuriate, initiate,
   install, institute, introduce, issue from, jerk, key up, kindle,
   lather up, launch, lie on, lie with, lift up, light the fuse,
   light up, loop in, madden, move, originate in, overexcite,
   palpitate, pant, pique, plug in, proceed from, quake, quaver,
   quiver, raise, raise up, rest, rest on, rest with, revolve on,
   ring in, rouse, set agoing, set astir, set fire to, set on fire,
   set on foot, set up, shake, shiver, shock, short, short-circuit,
   spring from, sprout from, squirm, stand on, start going, start up,
   steam up, stem from, step down, step up, stiffen, stir,
   stir the blood, stir the embers, stir the feelings, stir up,
   summon up, swell, swell with emotion, switch off, switch on,
   thrill, thrill to, throb, tingle, tingle with excitement, toss,
   toss and turn, tremble, tumble, turn off, turn on to, turn upon,
   twist and turn, twitch, twitter, usher in, wake, wake up, waken,
   warm, warm the blood, whip up, wiggle, work into, work up, wriggle,
   writhe