noun
: a lamp whose light passes through the sound track of a motion-picture film and enters a photoelectric cell causing the current fluctuations that actuate the loudspeaker
noun
: a lamp whose light passes through the sound track of a motion-picture film and enters a photoelectric cell causing the current fluctuations that actuate the loudspeaker
Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012