Meaning of RADAR in English

System that uses electromagnetic echoes to detect and locate objects.

It can also measure precisely the distance (range) to an object and the speed at which the object is moving toward or away from the observing unit. Radar (the name is derived from ra dio d etecting a nd r anging) originated in the experimental work of microwave radar system for military use. Radar is used today in identification and monitoring of artificial satellites in Earth orbit, as a navigational aid for airplanes and marine vessels, for air traffic control around major airports, for monitoring local weather systems, and for spotting "speeders."

Britannica English dictionary.      Английский словарь Британика.