The Collaborative International Dictionary of English v.0.48:

Scintillate \Scin"til*late\, v. i. [imp. & p. p. Scintillated;
   p. pr. & vb. n. Scintillating.] [L. scintillare,
   scintillatum, from scintilla a spark. Cf. Stencil.]
   1. To emit sparks, or fine igneous particles.
      [1913 Webster]

            As the electrical globe only scintillates when
            rubbed against its cushion.           --Sir W.
                                                  Scott.
      [1913 Webster]

   2. To sparkle, as the fixed stars.
      [1913 Webster]

WordNet (r) 3.0 (2006):

scintillate
    v 1: give off; "the substance scintillated sparks and flashes"
    2: reflect brightly; "Unquarried marble sparkled on the
       hillside" [syn: sparkle, scintillate, coruscate]
    3: emit or reflect light in a flickering manner; "Does a
       constellation twinkle more brightly than a single star?"
       [syn: twinkle, winkle, scintillate]
    4: physics: fluoresce momentarily when struck by a charged
       particle or high-energy photon; "the phosphor fluoresced"
    5: be lively or brilliant or exhibit virtuosity; "The musical
       performance sparkled"; "A scintillating conversation"; "his
       playing coruscated throughout the concert hall" [syn:
       sparkle, scintillate, coruscate]

Moby Thesaurus II by Grady Ward, 1.0:

41 Moby Thesaurus words for "scintillate":
   be brilliant, be merry with, blink, coruscate, crack a joke,
   crack wise, fleer at, fun, gibe at, glance, gleam, glimmer, glint,
   glisk, glisten, glister, glitter, jape, jest, joke, josh, kid,
   kid around, make a funny, make fun, make fun of, mock,
   play on words, poke fun at, pun, quip, ridicule, scoff at, shimmer,
   spangle, spark, sparkle, tinsel, twinkle, utter a mot, wisecrack