Meaning of RADAR in English

RADAR

■ noun a system for detecting the presence, direction, and speed of aircraft, ships, etc., by sending out pulses of radio waves which are reflected off the object back to the source.

Origin

1940s: from ra(dio) d(etection) a(nd) r(anging) .

Concise Oxford English vocab.      Сжатый оксфордский словарь английского языка.