\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.