petri-
petrifaction
petrification
petrify
petrine
petro-
petrochemical
petrochemistry
petrodollar
petrogenesis
petrogenetic
petroglyph
petroglyphic
petrograph
petrographer
petrographic
petrographical
petrographically
petrography
petroil
petrol
petrol bomb
petrol-engine
petrol station
petrol tank
petrolatum
petroleum
petroleum jelly
Petroleum revenue tax (PRI)
petroleur