de·​tec·​tor | \ di-ˈtek-tər \

Definition of detector

: one that detects: such as
a : a device for detecting the presence of electromagnetic waves or of radioactivity
b : a rectifier of high-frequency current used especially for extracting the intelligence from a radio signal

Keep scrolling for more

Synonyms for detector



Visit the Thesaurus for More 

Examples of detector in a Sentence

using metal detectors to improve safety at airports a motion detector to thwart burglaries

Recent Examples on the Web

Many public buildings in Nairobi, including the Riverside complex, have metal detectors and security guards sweeping cars for weapons and explosives. Gabriele Steinhauser, WSJ, "Questions Mount as Kenyan Hotel Siege Ends," 16 Jan. 2019 While hydrazine costs $85 to $100 per pound, the real costs come with the security needed to transport such a toxic substance: protective equipment, detectors, and waste disposal all add up. David Grossman, Popular Mechanics, "Plasma Thrusters Are About To Have Their Moment," 30 Aug. 2018 Vendors waved handheld metal detectors and displayed 3D surveillance cameras. Alexia Fernández Campbell, Vox, "I went to a huge conference on school safety. No one wanted to talk about gun control.," 30 July 2018 Missing were radiation detectors and small samples of plutonium and cesium used to calibrate them. Dan Goodin, Ars Technica, "Dangerous plutonium stolen from rental car in a hotel parking lot," 16 July 2018 The plant’s paint shops, which reportedly have suffered several small fires over the years, have received renovations worth at least $10.2 million since July 2016, according to BuildZoom, including work to install new fire detectors and sprinklers. David R. Baker,, "Tesla’s rush to crank up production revealed in building permits," 28 June 2018 Indeed, law enforcement officers on all campuses, metal detectors at entryways and trained school psychologists on all campuses were among the most common responses. Dan Sweeney,, "As Runcie presents school safety changes in Broward, some say good start, others call for his firing," 6 June 2018 Jackson also said schools should consider adding metal detectors in order to identify when students bring firearms on campus. Wilborn P. Nobles Iii,, "Students, parents march in second-line to raise gun violence awareness," 31 May 2018 One federal law already addresses some of the concerns: The Undetectable Firearms Act bans guns that can’t be spotted by walk-through metal detectors. German Lopez, Vox, "The battle to stop 3D-printed guns, explained," 1 Aug. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'detector.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of detector

1541, in the meaning defined above

Keep scrolling for more

Learn More about detector

Statistics for detector

Last Updated

18 Feb 2019

Look-up Popularity

Time Traveler for detector

The first known use of detector was in 1541

See more words from the same year

Keep scrolling for more

More Definitions for detector



English Language Learners Definition of detector

: a device that can tell if a substance or object is present : a device that detects the presence of something


de·​tec·​tor | \ di-ˈtek-tər \

Medical Definition of detector

: one that detects especially : a device for detecting the presence of electromagnetic waves or of radioactivity

Keep scrolling for more

More from Merriam-Webster on detector

Rhyming Dictionary: Words that rhyme with detector

Thesaurus: All synonyms and antonyms for detector

Spanish Central: Translation of detector

Nglish: Translation of detector for Spanish Speakers Encyclopedia article about detector

Comments on detector

What made you want to look up detector? Please tell us where you read or heard it (including the quote, if possible).


very full or close together

Get Word of the Day daily email!

Test Your Vocabulary

What did you just call me?! A Quiz

  • rows-of-various-emoji
  • If a member of the audience describes your speech as bombastic, does that person mean it is:
True or False

Test your knowledge - and maybe learn something along the way.


Test Your Knowledge - and learn some interesting things along the way.


Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!