Meaning of RADAR in English

n.1 a system for detecting the direction, range, or presence of aircraft, ships, and other (usu. moving) objects, by sending out pulses of high frequency electromagnetic waves.

2 the apparatus used for this.

Phrases and idioms:

radar trap the use of radar to detect vehicles exceeding a speed limit.

Etymology: radio detection and ranging

Oxford English vocab.      Оксфордский английский словарь.