lie detector

noun

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

Synonyms

• polygraph

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

While Doc Odd measures her pulse, Angela Bassett uses it like a lie detector and subjects her to questioning. —Rebecca Alter, Vulture, 2 Apr. 2025

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

Word History

First Known Use

1909, in the meaning defined above

Rhymes for lie detector

• eigenvector
• bisector
• collector
• connector
• corrector
• defector
• deflector
• director
• dissector
• effector
• ejector
• elector

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

ˈlī-di-ˌtek-tər 

: 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