| adieu |
an act of departing or signal of departure. [1/2 definitions] |
| alarm |
a bell or other loud noise used to signal danger. [1/2 definitions] |
| all clear |
the signal that an air raid or disaster drill is over. |
| AM |
a system of varying a radio signal's amplitude so as to impose the signal on a carrier wave; amplitude modulation. [1/2 definitions] |
| attenuator |
a device that reduces the strength of an electrical signal. |
| bandwidth |
the range of radio frequencies required to transmit a certain type of signal. |
| beacon |
a signal of light or radio waves that guides or warns ships or aircraft. |
| beam |
an electronic communications signal. [2/8 definitions] |
| beckon |
to signal to come using a motion of the head or hands. |
| beep |
a short, high sound that acts as a signal. |
| beeper |
a device that emits a beeping sound when it receives a radio signal, usu. used for paging those who carry it. |
| blinker |
a flashing light, especially one used on a car to signal that the car will turn and to show which way it will turn. |
| buzz |
to signal with a device that buzzes. [1/8 definitions] |
| buzzer |
any of numerous mechanical or electrical devices that signal by buzzing. |
| carrier |
the electromagnetic wave that is modulated to transmit a signal; carrier wave. [1/6 definitions] |
| cease-fire |
an order or signal to stop firing, as in war. [1/2 definitions] |
| cell phone |
a mobile telephone that operates using radio signals and therefore requires no wires. A cell phone is part of a system composed of many low-power radio transmitters located in "cells" across a region and will receive a radio signal from whichever transmitter in the system is closest; cellular phone. |
| cellular phone |
a mobile telephone that operates using radio signals and therefore requires no wires. A cellular phone is part of a system composed of many low-power radio transmitters located in "cells" across a region and will receive a radio signal from whichever transmitter in the system is closest; cell phone; mobile phone. |
| converter |
an electronic device that changes or adds frequencies of a television or radio signal. [1/5 definitions] |
| countersign |
a password or secret signal used to identify an ally. [2/4 definitions] |
| cue1 |
anything done or said during a play that is a signal for an actor to say or do something. [1/3 definitions] |