early 15c., petrifaccioun, "action or process of hardening, a turning to stone," from petrified on model of satisfaction, etc., or from Medieval Latin petrificacionis. From 1680s as "something petrified;" figurative sense is by 1722.
petition
petitioner
Petrarchan
petrel
Petri dish
petrifaction
petrification
petrified
petrify
petro-
petrochemical