Polygraph

Part of speech: noun

Pronunciation: /ˈpɒliɡɹæf/

Definitions

1. An apparatus that records various physiological indicators like heart rate, blood pressure, and respiration to ascertain truthfulness
2. A device employed to monitor bodily responses, such as respiration and heart rate, in order to evaluate honesty during questioning
3. An instrument that tracks multiple physical signals from a person to help detect deception

Etymology: The "poly" in polygraph is the Greek "polys," meaning "many," and "graph" comes from the Greek "graphein," meaning "to write" or "to record." Put together, the word describes something that writes or records many things at once. The original device did exactly that: it traced several bodily signals, such as blood pressure, pulse and breathing, onto moving paper, each on its own line. The noun is a compound built from these two Greek elements, a pattern that produced many scientific instrument names in the 19th and early 20th centuries, when inventors reached for classical roots to name new machines. The "-graph" ending appears in similar devices like the seismograph and the telegraph, so the word belongs to a family of recording instruments. Its earliest recorded use, according to the source, is not dated here, but the compound itself is clearly a modern coinage from classical parts rather than an ancient Greek word.

Synonyms: lie detector, truth detector, psychophysiological device, instrument, gadget