(1) A device that accepts signals. Contrast with "transmitter," which sends signals. The term is used generically to refer to "the side being sent to." For example, "by the time the signal gets to the receiver..." refers to whichever hardware device is at the other end of the communication.
(2) A unit of audio or audio/video equipment that serves as the primary control for a stereo or home theater system. See
stereo receiver,
A/V receiver and
head unit.