Source : Webster's Revised Unabridged Dictionary (1913)

Megascopic \Meg`a*scop"ic\, Megascopical \Meg`a*scop"ic*al\, a.
   1. (Physics) Of or pertaining to the megascope or the
      projection upon a screen of images of opaque objects.
      (b) Enlarged or magnified; -- said of images or of
          photographic pictures, etc.

   2. (Geol.) Large enough to be seen; -- said of the larger
      structural features and components of rocks which do not
      require the use of the microscope to be perceived. Opposed
      to {microscopic}.