lie detector

noun

1. a polygraph used to determine changes in certain body activities, as blood pressure, pulse, breathing, and perspiration, the results of which may be interpreted to indicate the truth or falsity of a person's answers under questioning.

lie detector

noun

1. a polygraph used esp by a police interrogator to detect false or devious answers to questions, a sudden change in one or more involuntary physiological responses being considered a manifestation of guilt, fear, etc See polygraph galvanic skin response

Word History and Origins

Origin of lie detector¹

An Americanism dating back to 1905–10

Example Sentences

Although they dress like nuns styled by Jean Paul Gaultier and hold titles like Reverend Mother, they adhere to a regimen of martial arts training and learn how to be living lie detectors.

From Salon

Employees in the DEA’s polygraph unit, which vets prospective agents, reported being pressured to pass candidates after they failed a lie detector test, report says.

From Los Angeles Times

Just a week earlier, he had been filming for the show, during which he failed a lie detector test.

From BBC

In a key clip, Ms Callaghan sobbed and shouted when the results of a lie detector test were revealed.

From BBC

On the day of the recording, Mrs Thaxter said her lodger had phoned and said he had failed the lie detector test.

From BBC