Quantcast
Merriam-Webster Logo
  • Dictionary
  • Thesaurus
  • Medical
  • Scrabble
  • Spanish Central
  • Learner's Dictionary

lie detector

noun

Simple Definition of lie detector

  • : a device used to measure the heart rate, breathing, etc., in order to find out if someone (such as a person suspected of a crime) is being honest

Full Definition of lie detector

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

Examples of lie detector

  1. The murder suspect failed a lie detector test.

  2. <hooked the suspect up to a lie detector before interrogating him about the robbery>



1909

First Known Use of lie detector

1909

Rhymes with lie detector


Medical Dictionary

lie detector

play
noun \ˈlī-di-ˌtek-tər\

Medical Definition of lie detector

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




Learn More about lie detector


Seen and Heard

What made you want to look up lie detector? Please tell us where you read or heard it (including the quote, if possible).

WORD OF THE DAY

February 9, 2016

marked by high spirits and laughter

Get Word of the Day daily email!

WORD GAMES

Take a 3-minute break and test your skills!

image1037863653

Which of the following refers to thin, bending ice, or to the act of running over such ice?

kittly-benders pince-nez duvet spindrift
Name That Thing

10 quick questions: hear them, spell them, and see how your skills compare to the crowd.

TAKE THE QUIZ
SCRABBLE® Sprint

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ