shale

From Middle English schale (“shell, husk; scale”), from Old English sċealu (“shell, husk, pod”), from Proto-Germanic *skalō (compare West Frisian skaal (“dish”), Dutch schaal (“shell”), schalie (“shale”), German Schale (“husk, pod”)), from Proto-Indo-European *(s)kelH- (“to split, cut”) (compare Lithuanian skalà (“splinter”), Old Church Slavonic скала (skala, “rock, stone”), Polish skała (“rock”), Albanian halë (“fish bone, splinter”), Sanskrit कल (kalá, “small part”)), from to split, cleave (compare Hittite [script needed] (iškalla, “to tear apart, slit open”), Lithuanian skélti (“to split”), Ancient Greek σκάλλω (skállō, “to hoe, harrow”)). Doublet of scale. See also shell.

• Rhymes: -eɪl

a shale outcrop on Mars

shale (countable and uncountable, plural shales)

1. A shell or husk; a cod or pod.
   • Chapman

     the green shales of a bean

2. (geology) A fine-grained sedimentary rock of a thin, laminated, and often friable, structure.
   • 2007 March 23, Patricia Leigh Brown, “The Window Box Gets Some Tough Competition”, in New York Times‎:

     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.

Before the mid 19th century, the terms shale, slate and schist were not sharply distinguished. Shales that are subject to heat and pressure alter into slate, then schist and finally to gneiss.

• oil shale
• shale oil
• shaley
• shaleionaire
• shaly

• gneiss
• schist
• slate

shale (third-person singular simple present shales, present participle shaling, simple past and past participle shaled)

1. To take off the shell or coat of.

• shell

• Hales, Heals, Sahel, Saleh, Selah, hales, halse, heals, leash, selah, sheal

shale

1. bus