Main Entry: ra·dar

Pronunciation: \ˈrā-ˌdär\

Function: noun

Usage: often attributive

Etymology: radio detecting and ranging

Date: 1941

1 : a device or system consisting usually of a synchronized radio transmitter and receiver that emits radio waves and processes their reflections for display and is used especially for detecting and locating objects (as aircraft) or surface features (as of a planet)
2 : range of notice <fell off the radar after losing their first three games>