petroleum

pe·tro·leum

noun \pə-ˈtrō-lē-əm, -ˈtrōl-yəm\

Definition of PETROLEUM

: an oily flammable bituminous liquid that may vary from almost colorless to black, occurs in many places in the upper strata of the earth, is a complex mixture of hydrocarbons with small amounts of other substances, and is prepared for use as gasoline, naphtha, or other products by various refining processes