Polygraph

Origin

poly- "much" + -graph "writing"

Full definition of polygraph

Noun

1. A device which measures and records several physiological variables such as blood pressure, heart rate, respiration and skin conductivity while a series of questions is being asked to a subject, in an attempt to detect lies.
2. (dated) An mechanical instrument for multiplying copies of a writing, resembling multiple pantographs.
3. (archaic) A collection of different works, either by one or several authors.

Synonyms

• (device recording physiological measurements) lie detector
• (dated instrument for copying) manifold writer, autopen

Verb

1. To administer a polygraph test.The FBI polygraphed the suspect but learned nothing because they already knew he was lying.