radar
RAY-dah
Radar (noun) means a system that detects and tracks objects by sending out radio waves and analyzing the signals that bounce back. Example: “The ship's radar showed a large storm moving in from the west.”
noun
1
A system that detects and tracks objects by sending out radio waves and analyzing the signals that bounce back.
"The ship's radar showed a large storm moving in from the west."
"Weather forecasters use radar to see where the rain is falling."
"Air traffic controllers use radar to track planes approaching the airport."
2
An informal, figurative sense: someone's awareness or instinct for noticing something.
"The problem was never on my radar until a customer complained."
"His radar for bad business deals kicked in immediately."
"The new hire is talented but flew under management's radar for months."
How to use radar
Learner’s notesIn plain EnglishA detection system using radio waves, or informally, a sharp instinct for spotting something.
Common mistake
Since "radar" began life as an acronym, it doesn't need capital letters in modern writing.
Easily confused with
Common pairings
on the radar
under the radar
radar screen
fly under the radar
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Word forms
- Plural
- radars
- Third person singular
- radars
- Past tense
- radared
Fill the gap
Can you complete this real example?
The ship's _____ showed a large storm moving in from the west.
Etymology
Originally an acronym for "radio detection and ranging", coined by US Navy officers in 1940; it later became an ordinary word in its own right.
Class of 1940
radar joined the language around 1940.
See the full Class of 1940 →
Synonyms
View more →Related words
Frequently asked questions
What does “radar” mean?
The word “radar” means a system that detects and tracks objects by sending out radio waves and analyzing the signals that bounce back. In plain terms, a detection system using radio waves, or informally, a sharp instinct for spotting something.
How do you pronounce “radar”?
“Radar” is pronounced RAY-dah (/ˈɹeɪˌdɑɹ/ in IPA).
How do you use “radar” in a sentence?
Here is “radar” used in a sentence: “Air traffic controllers use radar to track planes approaching the airport.”
What part of speech is “radar”?
“Radar” is a noun.
Where does the word “radar” come from?
The word “radar” dates back to around 1940. Originally an acronym for "radio detection and ranging", coined by US Navy officers in 1940; it later became an ordinary word in its own right.
Is “radar” a common word?
“Radar” is a fairly common word in modern English, usually learned at around the B2 level.
How many meanings does “radar” have?
“Radar” has 2 distinct senses listed in this dictionary. The most common is: a system that detects and tracks objects by sending out radio waves and analyzing the signals that bounce back.
What does the word "radar" stand for?
"Radar" is an acronym for "radio detection and ranging." It describes a system that detects and tracks objects by sending out radio waves and analysing the signals that bounce back.
What is the difference between "radar" and "sonar"?
"Radar" detects and tracks objects using radio waves, and is used mainly in the air and on land. "Sonar" does a similar job using sound waves and is used underwater, so the two systems suit different environments.
Is "radar" written in capitals?
Although "radar" began as an acronym, it is now treated as an ordinary word and written in lowercase in normal use. You only capitalise it at the start of a sentence, unlike acronyms that are still written in full capitals.
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