Petroleum

Part of speech: noun

Pronunciation: /pəˈtɹoʊliəm/

Definitions

1. A thick, flammable liquid mixture of hydrocarbons extracted from beneath the earth's surface, refined into fuels and other products
2. A naturally occurring liquid consisting mainly of hydrocarbons that is extracted from geological formations for use as fuel, lubrication, and various chemical products
3. This viscous fluid found underground is composed of hydrocarbons, which are refined into fuels, lubricants, and other petrochemicals for industrial uses

Etymology: "Petroleum" is built from two Greek-derived parts: "petra," meaning rock, and the Latin "oleum," meaning oil. The name is literally "rock oil," a description of crude oil as it emerges from the ground. The Medieval Latin "petroleum" was the source, and English borrowed the term directly from it as a learned word, which is why it looks so much like the Latin form rather than a worn-down everyday term. Its close relative is "petrol," which came into English through a different path and kept a more everyday life, especially in British usage for the fuel that runs cars. The two are doublets: one entered English as a scholarly borrowing, the other as a shorter, commercial-sounding word, and both trace back to the same Medieval Latin coinage. The pairing shows how a single old term can split into a formal name for the substance and a practical name for the product.

Synonyms: oil, crude oil