Source : Webster's Revised Unabridged Dictionary (1913)

Stroboscope \Strob"o*scope\, n. [Gr. ? a whirling + -scope.]
   1. An instrument for studying or observing the successive
      phases of a periodic or varying motion by means of light
      which is periodically interrupted.

   2. An optical toy similar to the phenakistoscope. See
      {Phenakistoscope}.

Source : WordNet®

stroboscope
     n : scientific instrument that provides a flashing light
         synchronized with the periodic movement of an object; can
         make moving object appear stationary [syn: {strobe}, {strobe
         light}]