shales

Noun

shale (countable and uncountable, plural shales)

1. A shell, scale or husk; a cod or pod.
   • the green shales of a beanc. 1610s, Homer (attributed), translated by George Chapman, The Crowne of all Homers Workes: Batrachomyomachia, or the Battaile of Frogs and Mise […], published 1624
2. A fine-grained sedimentary rock of a thin, laminated, and often friable, structure.
   • As on all large green roofs, the soil is not dirt exactly but a gravel-like growing medium of granulated pumice, shales, clays and other minerals.2007 March 23, Patricia Leigh Brown, “The Window Box Gets Some Tough Competition”, in The New York Times
3. (metonymically) The shale oil and shale gas segment of the oil and gas industry.
   • American shale’s placid responses to energy whirlwinds are becoming an enduring feature of the U.S. oil industry. In recent years, public drillers under investor pressure to be profitable have treated spiking oil prices as an opportunity to return more cash to shareholders—and lock in prices for...2026 March 4, Benoît Morenne, “Why American Frackers Aren’t Rushing to Pump More Oil: U.S. shale giants won’t budge from their plans, despite the market chaos”, in The Wall Street Journal

See all 4 meanings of shale