Definition of clinkered:
(n) :
Slag or ash produced by intense heat in a furnace, kiln or boiler that forms a hard residue upon cooling.
(n) :
A mass of bricks fused together by intense heat.
(n) :
An intermediate product in the manufacture of Portland cement, obtained by sintering limestone and alumino-silicate materials such as clay into nodules in a cement kiln.
(n) :
A very hard brick used for paving customarily made in the Netherlands.
(n) :
Hardened volcanic lava.
(n) :
A scum of oxide of iron formed in forging.