The definition of Over-the-air Tuner, Receiver

Over-the-air Tuner – (Maybe known as Receiver, Digital over-the-air Tuner, HDTV Over-the-air Tuner, Digital Tuner, Tuner, Digital Television Tuner, Over-the-air Receiver, Terrestrial TV Tuner, Terrestrial TV Receiver, Free-to-air Receiver) - The electronic portion of a digital TV, set-top box, media center or other electronic device that 'catches' the incoming signal from the viewer's antenna. However more has to be done to the signal before it's viewable. See Decoder and Demodulation. It can also be used to 'catch' standard analog TV signals.
A receiver includes the tuner and has additional functions.

http://en.wikipedia.org/wiki/Terrestrial_television

See the Interactive Television Institute.