-raf, -rȧf noun
Etymology: Greek polygraphos writing much, from poly- + -graphos (from graphein to write) — more at carve
1. : a voluminous or versatile writer
2. : an instrument for recording tracings of several different pulsations simultaneously (as of the pulse, blood pressure, and respiration) — compare pathometer
3. : lie detector — see keeler polygraph
4. : a cluster of two or more successive letters in cryptography