The Collaborative International Dictionary of English v.0.48:

Corpuscular \Cor*pus"cu*lar\ (k?r-p?s"k?-l?r), a. [Cf. F.
   corpusculaire.]
   Pertaining to, or composed of, corpuscles, or small
   particles.
   [1913 Webster]

   Corpuscular philosophy, that which attempts to account for
      the phenomena of nature, by the motion, figure, rest,
      position, etc., of the minute particles of matter.

   Corpuscular theory (Opt.), the theory enunciated by Sir
      Isaac Newton, that light consists in the emission and
      rapid progression of minute particles or corpuscles. The
      theory is now generally rejected, and supplanted by the
      undulatory theory.
      [1913 Webster]

WordNet (r) 3.0 (2006):

corpuscular theory
    n 1: (physics) the theory that light is transmitted as a stream
         of particles [syn: corpuscular theory, corpuscular
         theory of light] [ant: undulatory theory, wave theory,
         wave theory of light]