Source : Webster's Revised Unabridged Dictionary (1913)

Endoscope \En"do*scope\, n. [Endo- + -scope.] (Med.)
   An instrument for examining the interior of the rectum, the
   urethra, and the bladder.

Source : WordNet®

endoscope
     n : a long slender medical instrument for examining the interior
         of a bodily organ or performing minor surgery