This word is acceptable for play in the US & UK dictionaries that are being used in the following games:

• Lexulous
• Wordscraper
• Wordosaur

adj. Pertaining to or resembling shale.

"The side trail was too narrow for the cart, so Skip abandoned it at the turnoff and limped after the others on foot, down a rocky path that hugged the base of a shaley cliff for a hundred yards or so."