n. 1. Petroleum. [ Archaic and R. ] [ 1913 Webster ]

2. Same as gasoline; -- British usage. [ British ] [ PJC ]

n. (Chem. & Pharm.) A semisolid unctuous substance, neutral, and without taste or odor, derived from petroleum by distilling off the lighter portions and purifying the residue. It is a yellowish, fatlike mass, transparent in thin layers, and somewhat fluorescent. It is used as a bland protective dressing, and as a substitute for fatty materials in ointments. U. S. Pharm. [ 1913 Webster ]

☞ Petrolatum is the official name for the purified product. Cosmoline and vaseline are commercial names for substances essentially the same, but differing slightly in appearance and consistency or fusibility. [ 1913 Webster ]

n. [ NL., fr. L. petra a rock + oleum oil: cf. F. pétrole. Cf. Petrify, and Oil. ] 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. [ 1913 Webster ]

Petroleum spirit, a volatile liquid obtained in the distillation of crude petroleum at a temperature of 170° Fahr., or below. The term is rather loosely applied to a considerable range of products, including benzine and ligroin. The terms petroleum ether, and naphtha, are sometimes applied to the still more volatile products, including rhigolene, gasoline, cymogene, etc. [ 1913 Webster ]

{ ‖n. m. ‖n. f. } [ F. ] One who makes use of petroleum for incendiary purposes. [ 1913 Webster ]

n. (Chem.) A paraffin obtained from petroleum from Rangoon in India, and practically identical with ordinary paraffin. [ 1913 Webster ]

{ } a. Of or pertaining to petrology. [ 1913 Webster ]

adv. According to petrology. [ 1913 Webster ]

n. One who is versed in petrology. [ 1913 Webster ]

n. [ Petro + -logy. ] 1. The department of science which is concerned with the mineralogical and chemical composition of rocks, and with their classification: lithology. [ 1913 Webster ]

2. A treatise on petrology. [ 1913 Webster ]