Word of the day: clinker

The word of the day is clinker:

1. a mass of incombustible matter fused together, as in the burning of coal.
2. a hard Dutch brick, used especially for paving.
3. a partially vitrified mass of brick.
4. the scale of oxide formed on iron during forging.
5. Geology. a mass of vitrified material ejected from a volcano.

1769, from klincard (1641), a type of paving brick made in Holland, from Du. klinkaerd, from klinken "to ring" (as it does when struck), from M.Du., of imitative origin. 

(http://dictionary.reference.com/browse/clinker)

"The courtyard was made of clinker, which turned into dust in the summer and mud when it rained."

 - Caroline Moorehead, Village of Secrets