Meaning & use
radar
Last updated
Meanings
nouncountable or uncountabletechnical
A system that sends out radio waves and uses the echoes to find the position and speed of objects such as aircraft, ships and storms.
Grammar: Uncountable for the technology: tracked by radar. Countable for a device: a ship's radar.
Patterns
- on radar
- detected by radar
- a radar screen
The plane disappeared from the radar over the ocean.
Ships use radar to avoid hitting each other in thick fog.
The weather radar showed a storm moving toward the coast.
nounsingularfigurative
Your awareness or attention, as in whether you notice or are thinking about someone or something.
Grammar: Used in set phrases with on or under: on my radar, under the radar.
Patterns
- on someone's radar
- under the radar
- off the radar
The small company stayed under the radar until its product went viral.
That candidate is not on my radar yet.
The issue has come onto the minister's radar.
nouncountable
The device or screen that shows the detected objects.
Grammar: Used for the equipment itself: a radar was installed on the hill.
Patterns
- a radar station
- a radar screen
The pilot watched the radar for other aircraft.
Police used a hand-held radar to measure vehicle speed.
A new radar was fitted at the airport.
Word forms
| plural | radars |
|---|
Common combinations
- under the radar
- The band quietly built a following under the radar.
- on the radar
- The idea is finally on the radar of the board.
- radar screen
- A tiny dot moved across the radar screen.
- weather radar
- The weather radar showed heavy rain approaching.
- fly below the radar
- The plan flew below the radar of regulators.
- radar detector
- The driver was fined for using a radar detector.
Synonyms and how they differ
- sonar
- Sonar uses sound waves, mostly underwater, while radar uses radio waves in the air.
- lidar
- Lidar uses laser light instead of radio waves and is used in mapping and self-driving cars.
- awareness
- Awareness is the plain word for noticing something, while radar in the figurative sense is more idiomatic and informal.
- attention
- Attention means focused concentration, while radar often suggests general awareness.
Word family
- radar gun noun
- a hand-held device for checking speed
- radar station noun
- a base that tracks objects by radar
- radar operator noun
- a person who watches a radar screen
- radio noun
- related technology using radio waves
Commonly confused: radar or sonar?
radar vs sonar
Sonar uses sound underwater, while radar uses radio waves, so they are used in different settings.
Practice
The tiny startup stayed ___ the radar for years before anyone noticed it.
Choose one answer.
Under the radar means not noticed by others, which fits a company nobody paid attention to. Over the radar is not a fixed phrase and would not make sense here.
Make it your own
Write a sentence using “radar”, then check it and compare it with the examples above.