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

Though West failed a lie detector test about Parker’s death, he was never charged with a crime. —Meilan Solly, Smithsonian Magazine, 18 July 2024

According to the affidavit, Kevin Brown volunteered to take a lie detector test. —Richard Schlesinger, CBS News, 6 July 2024

However, the lie detector determined that untrue, because the crowd at the Forum knew every single word and went bar-for-bar for the entire six-minute song. —Angel Diaz, Billboard, 20 June 2024

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 Apr. 2024

Word History

First Known Use

1909, in the meaning defined above

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