coal

US /koʊl/
UK /koʊl/
"coal" picture
1.

a combustible black or dark brown sedimentary rock consisting mainly of carbonized plant matter, found in underground deposits and widely used as fuel.

:
The train was powered by coal.
Many power plants still burn coal to generate electricity.
2.

a piece of glowing or charred wood or other combustible material.

:
The campfire was reduced to glowing coals.
He poked at the hot coals with a stick.