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 posed to a subject, in an attempt to detect deception.

   “It used to be just a plain office with a chair and some instruments on a table. Then they got the new, fancy polygraph system.”

2. (dated)A mechanical instrument for multiplying copies of a writing, resembling multiple pantographs.
3. (archaic)A collection of different works, either by one or several authors.
4. A group of letters that represent a single phoneme.
5. Any group of letters treated as a single item.

   “A polygraph consists of an unspecified number of adjacent letters. A polygraph need not be recognisable as a word in a language but if we are attempting to decipher a message which is expected to be in English and we find the heptagraph MEETING it is much more promising than if we find a heptagraph such as DKRPIGX.”

6. An author who writes on many subjects.
7. A multidimensional directed graph.

verb

1. (transitive)To administer a polygraph test to.

   “The FBI polygraphed the suspect but learned nothing because they already knew he was lying.”