Source : Webster's Revised Unabridged Dictionary (1913)

Microscopic \Mi`cro*scop"ic\, Microscopical \Mi`cro*scop"ic*al\,
   a. [Cf. F. microscopique.]
   1. Of or pertaining to the microscope or to microscopy; made
      with a microscope; as, microscopic observation.

   2. Able to see extremely minute objects.

            Why has not man a microscopic eye?    --Pope.

   3. Very small; visible only by the aid of a microscope; as, a
      microscopic insect.

Source : WordNet®

microscopic
     adj 1: of or relating to or used in microscopy; "microscopic
            analysis"; "microscopical examination" [syn: {microscopical}]
     2: too small to be seen except under a microscope [syn: {microscopical},
         {small}] [ant: {macroscopic}]
     3: extremely precise with great attention to details; "examined
        it with microscopic care"
     4: infinitely or immeasurably small; "two minute whiplike
        threads of protoplasm"; "reduced to a microscopic scale"
        [syn: {infinitesimal}, {minute}]