WordNet (r) 3.0 (2006):

set off
    v 1: put in motion or move to act; "trigger a reaction";
         "actuate the circuits" [syn: trip, actuate, trigger,
         activate, set off, spark off, spark, trigger off,
         touch off]
    2: leave; "The family took off for Florida" [syn: depart,
       part, start, start out, set forth, set off, set
       out, take off]
    3: direct attention to, as if by means of contrast; "This dress
       accentuates your nice figure!"; "I set off these words by
       brackets" [syn: bring out, set off]
    4: cause to burst with a violent release of energy; "We exploded
       the nuclear bomb" [syn: explode, detonate, blow up,
       set off]
    5: make up for; "His skills offset his opponent's superior
       strength" [syn: cancel, offset, set off]
    6: set in motion or cause to begin; "The guide set the tour off
       to a good start"
    7: provoke or stir up; "incite a riot"; "set off great unrest
       among the people" [syn: incite, instigate, set off,
       stir up]

Moby Thesaurus II by Grady Ward, 1.0:

265 Moby Thesaurus words for "set off":
   actuate, adjoin, adorn, allocate, allot, analogize, analyze,
   anatomize, appoint, appropriate to, array, assign, assign to,
   assimilate, atomize, atone for, backfire, balance,
   be at cross-purposes, be off, be opposed to, bear for, bear up for,
   bear up to, beautify, become one, bedeck, bedizen, befringe, bind,
   blast, blazon, blow out, blow up, border, bound, break for,
   bring into analogy, bring into comparison, burst, bust, change,
   chop logic, circulate, clash, color, compare, compare and contrast,
   compare with, conflict, conflict with, confront, contradict,
   contradistinguish, contrapose, contrast, contrast with, contravene,
   controvert, counter, counteract, counterbalance, countercheck,
   counterpoise, counterpose, countervail, counterweigh, counterwork,
   dandify, dash for, deck, deck out, decorate, demarcate, demark,
   destine, desynonymize, detail, detonate, difference, differentiate,
   discharge, discriminate, disequalize, disjoin, distinguish,
   diversify, divide, dizen, doll up, draw a comparison,
   draw a parallel, draw the line, dress, dress up, earmark, edge,
   embellish, emblazon, embroider, enframe, enkindle, enrich,
   equiponderate, explode, fate, fig out, fire, fix up, frame, fringe,
   fulminate, furbish, garnish, get off, glamorize, go for, go forth,
   go off, grace, gussy up, hem, hit for, individualize, individuate,
   issue, issue forth, juxtapose in opposition, kindle, lap, lay for,
   lay off, lay out, let off, light the fuse, liken, liken to, line,
   list, lot, make a distinction, make assignments, make for, make up,
   make up to, march, marge, margin, marginate, mark, mark off,
   mark out, mark out for, mark the interface, match, measure against,
   measure off, measure out, metaphorize, modify, offset, oppose,
   oppugn, ordain, ornament, outset, outstart, outweigh, pace off,
   paint, parallel, particularize, personalize, pick out,
   place against, play at cross-purposes, portion off, prank,
   prank up, preen, prettify, pretty up, primp, primp up, prink,
   prink up, purfle, purl, put forth, redecorate, redeem, redo,
   refine a distinction, refurbish, relate, reserve, restrict,
   restrict to, rim, rule off, run a comparison, run counter to,
   run for, sail for, sally, sally forth, schedule, screen,
   screen out, segregate, select, separate, set, set a limit,
   set apart, set aside, set forth, set forward, set in contrast,
   set in opposition, set off against, set out, set out for,
   set over against, sever, severalize, shoot, side, sieve, sieve out,
   sift, sift out, similize, skirt, smarten, smarten up, sort,
   sort out, spark, specialize, split hairs, spruce up, square,
   square up, start, start off, start out, steer for, step off,
   strike out, subdivide, subtilize, tag, titivate, touch off,
   trick out, trick up, trigger, trim, vary, verge, view together,
   weigh, weigh against, winnow