radar
UK: ˈreɪdɑː | US: ˈreɪdɑr
n. a system for detecting the position, movement, and speed of objects using radio waves
n. (figuratively) a method or device for gathering information or monitoring activity
"Radar" is an acronym coined in 1941 from "Radio Detection And Ranging." It reflects the technology's function of using radio waves to detect and measure the distance of objects. The word's structure preserves the original acronym components, making it a rare example of a term that entered common usage while retaining its technical origins.
The aircraft's radar detected a storm ahead.
Scientists use radar to track migratory birds.
The police officer checked the speed of the car with a radar gun.
Meteorologists rely on radar to predict severe weather.
The submarine remained hidden by avoiding radar detection.