lie detector

noun

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

Synonyms of lie detector

• 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

What was Jordan’s reaction to the lie detector test coming back as inconclusive? —Jason Pham, StyleCaster, 13 Nov. 2025

The duo, who star together in the new thriller Die My Love, sat down for a lie detector test interview with Vanity Fair. —Catherine Santino, PEOPLE, 13 Nov. 2025

In an unexpected twist, however, Lyonne will not be returning as traveling detective/human lie detector Charlie Cale. —Christian Zilko, IndieWire, 13 Nov. 2025

Some of this involves a lie detector test and a cross-state road trip featuring the heavily pregnant Mayci Neeley and Mikayla Matthews, who act like this season’s Statler and Waldorf. —Peter White, Deadline, 13 Nov. 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