The Collaborative International Dictionary of English v.0.48:

Scintillation \Scin`til*la"tion\, n. [L. scintillatio: cf. F.
   scintillation.]
   1. The act of scintillating.
      [1913 Webster]

   2. A spark or flash emitted in scintillating.
      [1913 Webster]

            These scintillations are . . . the inflammable
            effluences discharged from the bodies collided.
                                                  --Sir T.
                                                  Browne.
      [1913 Webster]

WordNet (r) 3.0 (2006):

scintillation
    n 1: (physics) a flash of light that is produced in a phosphor
         when it absorbs a photon or ionizing particle
    2: a rapid change in brightness; a brief spark or flash [syn:
       twinkle, scintillation, sparkling]
    3: a brilliant display of wit
    4: the quality of shining with a bright reflected light [syn:
       glitter, glister, glisten, scintillation, sparkle]
    5: the twinkling of the stars caused when changes in the density
       of the earth's atmosphere produce uneven refraction of
       starlight