lie detector

noun

: a polygraph for detecting physiological evidence (such as change in heart rate) of the tension that accompanies lying

Examples of lie detector in a Sentence

The murder suspect failed a lie detector test. hooked the suspect up to a lie detector before interrogating him about the robbery
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Popularly known as lie detector tests, polygraphs monitor bodily responses such as blood pressure, changes in a person’s breathing, and sweating on the palms. Emily Hallas, The Washington Examiner, 29 Apr. 2025 There were travel restrictions to prevent leaks, and even discussions about subjecting employees to lie detector tests. Sheon Han, Wired News, 27 Mar. 2025 In late March, Hegseth's chief of staff, Joe Kasper, issued a memo warning that those suspected of disclosing sensitive information could be subject to lie detector tests. Tom Vanden Brook, USA Today, 15 Apr. 2025 At the Homeland Security Department, Secretary Kristi Noem pledged this month to step up lie detector tests on employees in an effort to identify those who may be leaking information about operations to the media. Tara Copp, Los Angeles Times, 22 Mar. 2025 See All Example Sentences for lie detector

Word History

First Known Use

1909, in the meaning defined above

Time Traveler
The first known use of lie detector was in 1909

Browse Nearby Words

Cite this Entry

“Lie detector.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/lie%20detector. Accessed 5 May. 2025.

Kids Definition

lie detector

noun
: an instrument for detecting bodily changes (as an increase in heart rate) that are considered to go along with lying

Medical Definition

lie detector

noun
: a polygraph for detecting physiological evidence (as change in heart rate) of the tension that accompanies lying

Legal Definition

lie detector

noun
lie de·​tec·​tor
: an instrument for detecting physiological evidence of the tension that accompanies lying compare polygraph

More from Merriam-Webster on lie detector

Last Updated: - Updated example sentences
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