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

In his letter to Weber, Curtis promised to take a lie detector test after each election. —Los Angeles Times, 25 Mar. 2026

Her work has prompted sweeping changes to laws and regulations, including a California-wide ban on a debunked lie detector technology used to interrogate prisoners. —Susie Neilson, San Francisco Chronicle, 5 Mar. 2026

Maury Povich spent decades at the center of one of daytime television’s most polarizing phenomena, presiding over paternity tests, lie detector results and the kind of raw confrontations that defined the height of ’90s talk TV. —Dave Quinn, PEOPLE, 28 Jan. 2026

Turning truth into a literal currency through a lie detector test feels perfectly aligned with this year’s theme. —Annika Pham, Variety, 16 Jan. 2026

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