What is the meaning of Clinker?

A very hard brick used for paving customarily made in the Netherlands.

A mass of bricks fused together by intense heat.

Slag or ash produced by intense heat in a furnace, kiln or boiler that forms a hard residue upon cooling.

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.

Hardened volcanic lava.

A scum of oxide of iron formed in forging.

To convert or be converted into clinker.

Someone or something that clinks.

fetters.

A style of boatbuilding using overlapping planks.

clinker

Source: wiktionary.org