The Collaborative International Dictionary of English v.0.48:

Coruscation \Cor`us*ca"tion\ (k?r`?s-k?"sh?n), n. [L.
   coruscatio: cf. F. coruscattion.]
   1. A sudden flash or play of light.
      [1913 Webster]

            A very vivid but exceeding short-lived splender, not
            to call ?t a little coruscation.      --Boyle.
      [1913 Webster]

   2. A flash of intellectual brilliancy.
      [1913 Webster]

            He might have illuminated his times with the
            incessant cor??cations of his genius. --I. Taylor.

   Syn: Flash; glitter; blaze; gleam; sparkle.
        [1913 Webster]

WordNet (r) 3.0 (2006):

coruscation
    n 1: the occurrence of a small flash or spark [syn: glitter,
         sparkle, coruscation]
    2: a sudden or striking display of brilliance; "coruscations of
       great wit"