The Collaborative International Dictionary of English v.0.48:

Titillate \Tit"il*late\ (t[i^]t"[i^]l*l[=a]t), v. t. & i. [imp.
   & p. p. Titillated (t[i^]t"[i^]l*l[=a]`t[e^]d); p. pr. &
   vb. n. Titillating.] [L. titillatus, p. p. of titillare.]
   1. To tickle; as, to titillate the nose with a feather.
      [1913 Webster]

            The pungent grains of titillating dust. --Pope.
      [1913 Webster]

   2. To arouse an agreeable sensation in; as, to titillate
      one's imagination; to titillate one's audience; to
      titillate the senses.
      [PJC]

WordNet (r) 3.0 (2006):

titillate
    v 1: touch (a body part) lightly so as to excite the surface
         nerves and cause uneasiness, laughter, or spasmodic
         movements [syn: tickle, titillate, vellicate]
    2: excite pleasurably or erotically; "A titillating story
       appeared in the usually conservative magazine"

Moby Thesaurus II by Grady Ward, 1.0:

66 Moby Thesaurus words for "titillate":
   affect the interest, amuse, appeal, attract, be attractive,
   becharm, beckon, beguile, bewitch, captivate, carry away, charm,
   concern, convulse, delectate, delight, divert, enchant, engage,
   enliven, enrapture, enravish, entertain, enthrall, entrance,
   excite, excite interest, exhilarate, fascinate, fetch, flush,
   fracture one, freak out, give a thrill, imparadise, interest,
   intoxicate, invite, involve in, kill, knock dead, knock out,
   loosen up, pique, provoke, raise a laugh, raise a smile, ravish,
   recreate, refresh, regale, relax, send, slay, solace, stimulate,
   summon, tantalize, tease, tempt, thrill, tickle, tickle pink,
   transport, whet the appetite, wow