Beeper is a simple program that emits a sound when newlines occur in standard input. It is useful in conjunction with commands like grep, find, and tail.
a radio transmitter, usually battery operated, which emits periodic signals that can be picked up by a radio receiver
A colloquial term for a mobile pager - one you carry on your belt or in your purse. In the very beginning when pagers went off, they made beeping sounds. Thus, they became known as beepers.