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

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

Earlier this month, Homeland Security Secretary Kristi Noem pledged to use lie detector tests on employees to identify those who may be leaking information about operations to the media. —CBS News, 22 Mar. 2025

The star of Russian Doll plays Charlie Cale, a human lie detector on the run from a shady casino enforcer (Benjamin Bratt). —Brian Tallerico, Vulture, 18 Mar. 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