petroleum

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A thick, flammable, yellow-to-black mixture of gaseous, liquid, and solid hydrocarbons that occurs naturally beneath the earth's surface, can be separated into fractions including natural gas, gasoline, naphtha, kerosene, fuel and lubricating oils, paraffin wax, and asphalt and is used as raw material for a wide variety of derivative products.

Century Dictionary and Cyclopedia

1. n. An oily substance of great economical importance, especially as a source of light, occurring naturally oozing from crevices in rocks, or floating on the surface of water, and also obtained in very large quantity in various parts of the world by boring into the rock; rock-oil. Petroleum was known to the Persians, Greeks, and Romans under the name of naphtha; the less liquid varieties were calledα%27σφαλτος by the Greeks, and bitumen was with the Romans a generic name for all the naturally occurring hydrocarbons which are now included under the names of asphaltum, maltha, and petroleum. The last name was not in use in classic times. The existence of petroleum in Pennsylvania and New York has been known from almost the earliest time of the settlement of those States by Europeans, but it was not until 1859, when oil was obtained by boring at Titusville on Oil Creek, a branch of the Allegheny River, that it began to be of commercial importance. At the present time the production of crude petroleum reaches an amount nearly equal to thirty millions of barrels a year, and the value of the exports of this article in various forms amounts to almost $50, 000, 000 a year, nearly all the material exported being furnished by the oil-fields of Pennsylvania and western New York. The crude oil undergoes refining, and is put upon the market in various forms (see kerosene, naphtha, rhigolene, etc.), but much the largest part of this product has the form of an oil suitable for burning in lamps in all parts of the world. The only other oil-producing region in the world at all comparing with that of Pennsylvania and New York is at and near Baku, on the Caspian, where the existence of oil has been known from time immemorial, but where its commercial importance has only recently been realized. The exported petroleums of the United States are chiefly from rocks of Devonian age; those of Baku occur in the Tertiary. An important part of the transportation of the crude material in the United States is effected by pipes laid beneath the surface, through which the oil is forced.
2. n. Of the entire product of petroleum throughout the world approximately 50 per cent. is furnished by Russia, 40 per cent, by the United States, and 10 per cent. by Canada, Austria, Rumania, the Sunda Islands, Burmah, Japan, and (in quite small proportion) Germany, South America, and Italy. California, Texas, and Kansas have of late largely increased their output, chiefly of crude fuel-oil, while in Pennsylvania, Ohio, and West Virginia there has been a diminished yield. It should be noted that American and Russian petroleum differ materially in chemical composition, the former consisting mainly of hydrocarbons of the paraffin series, while the latter represent chiefly naphthenes, isomeric but not identical with the members of the olefine series.

Wiktionary

1. n. A flammable liquid ranging in color from clear to very dark brown and black, consisting mainly of hydrocarbons, occurring naturally in deposits under earth surface.

GNU Webster's 1913

1. n. Rock oil, mineral oil, or natural oil, a dark brown or greenish inflammable liquid, which, at certain points, exists in the upper strata of the earth, from whence it is pumped, or forced by pressure of the gas attending it. It consists of a complex mixture of various hydrocarbons, largely of the methane series, but may vary much in appearance, composition, and properties. It is refined by distillation, and the products include kerosene, benzine, gasoline, paraffin, etc.

WordNet 3.0

1. n. a dark oil consisting mainly of hydrocarbons