WordNet (r) 3.0 (2006):

turn off
    v 1: cause to stop operating by disengaging a switch; "Turn off
         the stereo, please"; "cut the engine"; "turn out the
         lights" [syn: switch off, cut, turn off, turn out]
         [ant: switch on, turn on]
    2: make a turn; "turn off at the parking area"
    3: cause to feel intense dislike or distaste [syn: turn off,
       put off]

Moby Thesaurus II by Grady Ward, 1.0:

109 Moby Thesaurus words for "turn off":
   amplify, ax, blunt, boot, boot out, bounce, bow out, break, bump,
   bundle, bundle off, bust, can, cashier, charge, chill, close, cool,
   cut, damp, dampen, deflect, defrock, degrade, demote, deplume,
   depose, deprive, deter, disaffect, disbar, discharge, discourage,
   disemploy, disincline, disinterest, dismiss, displace, displume,
   distract, divert, drop, drum out, electrify, energize, expel, fire,
   furlough, galvanize, generate, gibbet, give the air, give the ax,
   give the gate, hustle out, indispose, kick, kick out,
   kick upstairs, kill, lay off, let go, let out, loop in,
   make redundant, noose, pack off, pension off, plug in, put off,
   quench, read out of, release, remove, repel, replace, retire, sack,
   scrag, send away, send off, send packing, separate forcibly, shock,
   short, short-circuit, show the door, show the gate, shut,
   shut down, shut off, step down, step up, stiffen, string up, strip,
   superannuate, surplus, suspend, switch off, switch on, terminate,
   turn aside, turn away, turn from, turn on, turn out, unfrock,
   wean from