clinker

clinker is a   Noun

Definition:

[1] A mass composed of several bricks run together by the action of the fire in the kiln.

[2] Scoria or vitrified incombustible matter, formed in a grate or furnace where anthracite coal in used; vitrified or burnt matter ejected from a volcano; slag.

[3] A scale of oxide of iron, formed in forging.

[4] A kind of brick. See Dutch klinker, under Dutch.

Synonyms: