Other forms: radars
Radar is a system that finds distant objects by bouncing radio waves off them. Radar screen, under the radar, a radar station.
It changed the Second World War, because Britain could see aircraft coming before they arrived. Under the radar means unnoticed, and on my radar means being watched, both from the screen. The name began as initials for radio detection and ranging.
1nounradarA system that finds distant objects by bouncing radio waves off them.
“The plane disappeared from the radar somewhere over the sea.”
radar is a system.
An acronym of radio detection and ranging, coined by the United States Navy in 1940.
The is derived from RADAR by anacronymic evolution. RADAR is an ra(dio) d(etection) a(nd) r(anging) which was by Lieutenant-Commander Samuel M. Tucker and Lieutenant-Commander F. R. Furth of the United States Navy in November 1940. The is probably derived from the noun.
Etymology from Wiktionary, CC BY-SA