The Collaborative International Dictionary of English v.0.48:

Stimulate \Stim"u*late\, v. t. [imp. & p. p. Stimulated; p.
   pr. & vb. n. Stimulating.] [L. stimulatus, p. p. of
   stimulare to prick or goad on, to incite, fr. stimulus a
   goad. See Stimulus.]
   1. To excite as if with a goad; to excite, rouse, or animate,
      to action or more vigorous exertion by some pungent motive
      or by persuasion; as, to stimulate one by the hope of
      reward, or by the prospect of glory.
      [1913 Webster]

            To excite and stimulate us thereunto. --Dr. J.
                                                  Scott.
      [1913 Webster]

   2. (Physiol.) To excite; to irritate; especially, to excite
      the activity of (a nerve or an irritable muscle), as by
      electricity.
      [1913 Webster]

   Syn: To animate; incite; encourage; impel; urge; instigate;
        irritate; exasperate; incense.
        [1913 Webster]

WordNet (r) 3.0 (2006):

stimulate
    v 1: act as a stimulant; "The book stimulated her imagination";
         "This play stimulates" [syn: stimulate, excite] [ant:
         dampen, stifle]
    2: cause to do; cause to act in a specified manner; "The ads
       induced me to buy a VCR"; "My children finally got me to buy
       a computer"; "My wife made me buy a new sofa" [syn: induce,
       stimulate, cause, have, get, make]
    3: stir the feelings, emotions, or peace of; "These stories
       shook the community"; "the civil war shook the country" [syn:
       stimulate, shake, shake up, excite, stir]
    4: cause to be alert and energetic; "Coffee and tea stimulate
       me"; "This herbal infusion doesn't stimulate" [syn:
       stimulate, arouse, brace, energize, energise, perk
       up] [ant: calm, de-energise, de-energize, sedate,
       tranquilize, tranquillise, tranquillize]
    5: cause to occur rapidly; "the infection precipitated a high
       fever and allergic reactions" [syn: induce, stimulate,
       rush, hasten]
    6: stir feelings in; "stimulate my appetite"; "excite the
       audience"; "stir emotions" [syn: stimulate, excite,
       stir]
    7: provide the needed stimulus for [syn: provoke, stimulate]

Moby Thesaurus II by Grady Ward, 1.0:

146 Moby Thesaurus words for "stimulate":
   activate, actuate, affect the interest, animate, animating, arouse,
   attract, awaken, brace, brace up, bracing, bring forth, bring out,
   bring to light, brisk, brisken, buck up, call forth, call out,
   call up, cheer, chirk up, compel, concern, cultivate, deduce,
   derive, drag out, draw forth, draw out, dynamize, educe, electrify,
   elicit, encourage, energize, enliven, enlivening, evoke, excite,
   excite interest, exhilarate, exhilarating, exhilarative, fascinate,
   fillip, fire, force, fortify, foster, fresh up, freshen,
   freshen up, fuel, galvanize, get from, get out of, goad, hearten,
   impel, incite, increase, induce, inflame, infuse life into,
   inspire, inspiring, inspirit, interest, intoxicating, invigorate,
   invite, involve in, jazz up, jolt, kindle, lively, liven,
   make sensitive, motivate, move, move to action, nourish, obtain,
   pep up, perk up, pick up, pique, procure, promote, prompt, propel,
   provocative, provoke, quicken, quickening, reanimate, recreate,
   refine, refresh, refreshen, regale, reinvigorate, renew,
   resuscitate, revive, revivify, rouse, rousing, secure, seminal,
   sensibilize, sensitize, set in motion, set up, sharpen, snap up,
   spark, spirit up, spur, stimulating, stimulative, stir, stir up,
   stirring, suggestive, summon forth, summon up, tantalize, tickle,
   titillate, tonic, vitalize, vitalizing, vivify, wake up, waken,
   wangle, wangle out of, warm, whet, whip up, winkle out, worm out,
   worm out of, zip up