polygraph

American  

[pol-i-graf, -grahf] / ˈpɒl ɪˌgræf, -ˌgrɑf /

noun

1. an instrument for receiving and recording simultaneously tracings of variations in certain body activities.

2. a test using such an instrument to determine if a person is telling the truth.

3. lie detector.

4. an apparatus for producing copies of a drawing or writing.

5. a prolific or versatile author.

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verb (used with object)

1. to test (a person) with a polygraph.

polygraph British  

/ -ˌɡræf, ˌpɒlɪˈɡræfɪk, ˈpɒlɪˌɡrɑːf /

noun

1. an instrument for the simultaneous electrical or mechanical recording of several involuntary physiological activities, including blood pressure, skin resistivity, pulse rate, respiration, and sweating, used esp as a would-be lie detector

2. a device for producing copies of written, printed, or drawn matter

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Other Word Forms

• polygrapher noun
• polygraphic adjective
• polygraphically adverb
• polygraphist noun

Etymology

Origin of polygraph

1795–1805 polygraph for def. 1; 1920–25 polygraph for def. 3; < Greek polýgraphos writing much. See poly-, -graph

Example Sentences

One week after her first test, she submitted to another polygraph.

From Slate • Apr. 6, 2026

The DEA is supporting the Bolivian government as it conducts "reliability" screens on anti-narcotics officers using polygraph lie detectors.

From Barron's • Apr. 1, 2026

Perez requested a polygraph test and failed it, Flores testified.

From Los Angeles Times • Feb. 19, 2026

The West Wing actor's defence team submitted more than 70 letters from people vouching for his character and said that he underwent and passed a polygraph test pertaining to the allegations against him.

From BBC • Jan. 20, 2026

They had already been briefed on the Tolkachev case when the CIA learned some unsavory things about Edward Lee Howard's past, including theft and lying on a polygraph test.

From "Spies: The Secret Showdown Between America and Russia" by Marc Favreau