polygraph (n.) Look up polygraph at Dictionary.com
1794, "mechanical device for making multiple copies of something written or drawn," from Greek polygraphos "writing much," from polys "much, many" (from PIE root *pele- (1) "to fill") + graphos "writing," from graphein "to write" (see -graphy).

Meaning "instrument for recording several pulsations of the body at the same time" is 1871; first used as a lie detector 1921. Related: Polygraphy (1590s); polygraphic (1771).