| 释义 |
pe·tro·leum
\pə̇.ˈtrōlēəm, -lyəm\ noun
(-s)
Usage: often attributive
Etymology: Medieval Latin, fr Latin petr- + oleum oil — more at oil
1. : an oily flammable bituminous liquid that in the crude state often has a very disagreeable odor and may vary from almost colorless to black but is usually of a dark brown or greenish hue and sometimes fluorescent, that occurs in many places in the upper strata of the earth either in seepages or in reservoir formations from which it is obtained by drilling and pumping if necessary, that is essentially a complex mixture of hydrocarbons of different types with small amounts of other substances (as oxygen compounds, sulfur compounds, nitrogen compounds, resinous and asphaltic components, and metallic compounds), that is sometimes classed as paraffin-base, asphalt-base or naphthene-base, or mixed-base, and that is subjected to various refining processes (as fractional distillation, cracking, catalytic re-forming, hydroforming, alkylation, polymerization) for producing useful products (as gasoline, naphtha, kerosine, fuel oils, lubricants, waxes, asphalt, coke, and chemicals) — called also mineral oil, rock oil
2. : any of various substances (as natural gas or shale oil) similar in composition to petroleum |