Shale

n.	1.	A shell or husk; a cod or pod.
	2.	(Geol.) A fine-grained sedimentary rock of a thin, laminated, and often friable, structure. Bituminous shale See under Bituminous.
v. t.	1.	To take off the shell or coat of; to shell. Life, in its upper grades, was bursting its shell, or was shaling off its husk. - I. Taylor.

Noun

1.

shale - a sedimentary rock formed by the deposition of successive layers of clay

humic shale, oil shale, sedimentary rock