Source : Webster's Revised Unabridged Dictionary (1913)

Photodrome \Pho"to*drome\, n. [Photo- + Gr. ? to run.] (Physics)
   An apparatus consisting of a large wheel with spokes, which
   when turning very rapidly is illuminated by momentary flashes
   of light passing through slits in a rotating disk. By
   properly timing the succession of flashes the wheel is made
   to appear to be motionless, or to rotate more or less slowly
   in either direction.