1A code or cipher; the action or practice of creating, writing, or deciphering such a code. Now frequently historical.
2Copious writing or literary work; literary productiveness.
3The action or practice of using a mechanical or chemical process to produce copies of pictures, writing, etc.
4The use of a polygraph to record several physiological characteristics simultaneously; the interpretation of data from a polygraph.
Late 16th century; earliest use found in Richard Harvey (d. 1630), astrologer and polemicist. From post-classical Latin polygraphia, poligraphia code or cipher, fact of writing much from Hellenistic Greek πολυγραϕία fact of writing much from πολυγράϕος (adjective) writing much + ancient Greek -ία.