Shale

• POS: Noun

CIDE DICTIONARY

Shale, n. [AS. scealy, scalu. See Scalme, and cf. Shell.].

•  A shell or husk; a cod or pod.  Chapman.  [1913 Webster]
•  A fine-grained sedimentary rock of a thin, laminated, and often friable, structure.  [1913 Webster]

Bituminous shale. See under Bituminous.

Shale, v. t. 

 To take off the shell or coat of; to shell.  [1913 Webster]
"Life, in its upper grades, was bursting its shell, or was shaling off its husk."  [1913 Webster]

OXFORD DICTIONARY

Shale, n. soft finely stratified rock that splits easily, consisting of consolidated mud or clay.

Idiom

shale oil oil obtained from bituminous shale.

Derivative

shaly adj.

Etymology

prob. f. G Schale f. OE sc(e)alu rel. to ON sk{aacute}l (see SCALE(2))