lie detector


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

Example Sentences

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 Just as Pinocchio’s nose reflexively signaled falsehood, so does our digital lie detector. Tom Van Laer, Discover Magazine, 29 June 2016 Sajudin apparently passed a lie detector test on the idea, prompting AMI to pay him for the exclusive rights to the story, all in order to kill it. Prem Thakker, The New Republic, 4 Apr. 2023 Vasya, failing a lie detector test when he’s asked about his criminal connections; Kolya, suspended in a swimming pool in a spinal-corrective brace, or stacking books up on a chair to compensate for his short stature when getting a passport photo taken. Jessica Kiang, Variety, 7 Oct. 2022 The couple takes a lie detector test. Starr Bowenbank, ELLE, 29 May 2022 Maybe the biggest lie of all is that lie detectors can work. Steven Levy, WIRED, 3 Mar. 2023 Watch Tatum’s full lie detector interview in the video below. Zack Sharf, Variety, 17 Jan. 2023 And according to Vanity Fair's lie detector technician, that is the truth. Kathleen Walsh, Glamour, 16 Dec. 2022 Check out Khloe and Kourtney on Vanity Fair’s lie detector test series above. Alexis Oatman, cleveland, 16 Dec. 2022 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'lie detector.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

First Known Use

1909, in the meaning defined above

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

Dictionary Entries Near lie detector

Cite this Entry

“Lie detector.” Dictionary, Merriam-Webster, Accessed 9 Jun. 2023.

Kids Definition

lie detector

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

Medical Definition

lie detector

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

Legal Definition

lie detector

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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