coal

The word “coal” means a black or dark brown rock, formed from ancient plant matter, burned as fuel. In plain terms, a rock burned for fuel, or a burning ember from a fire.

“Coal” is pronounced kohl (/koʊl/ in IPA).

Here is “coal” used in a sentence: “The old house was heated with coal.”

“Coal” is a noun.

The word “coal” comes from Old English. From Old English col, from a very old Germanic word ultimately meaning "to burn" or "to shine".

“Coal” is a fairly common word in modern English, usually learned at around the B1 level.

“Coal” has 2 distinct senses listed in this dictionary. The most common is: a black or dark brown rock, formed from ancient plant matter, burned as fuel.

Coal is a natural rock, a fossil fuel dug from the ground and formed from plants buried for millions of years. Charcoal is man-made, produced by heating wood with little air until only carbon remains. Coal is mined; charcoal is manufactured, and it is the lighter fuel used on barbecues.

Coal forms over millions of years from the remains of ancient plants. When swampy forests died, the plant matter was buried under layers of sediment. Heat and pressure gradually drove out water and gases, concentrating the carbon and hardening it into the black rock we mine and burn today.

Coal is graded by how much carbon it holds and how long it has formed. The main ranks are lignite (soft and brown), sub-bituminous, bituminous, and anthracite (hard, shiny, and highest in carbon). Higher-rank coals are older, denser, and release more energy when burned.

No. Coal is a non-renewable fossil fuel. It took many millions of years to form, so the supply we burn cannot be replaced within any human timescale. Because burning it also releases carbon dioxide and other pollutants, many countries are moving toward renewable energy sources instead.