What does coal mean?
Coal is a hard, black, carbon-rich rock formed over millions of years from the buried remains of ancient vegetation, and it has served as one of humanity's most important sources of fuel. Burned for heat, electricity generation, and industrial processes such as steelmaking, it powered the Industrial Revolution and remains a major energy source worldwide, though its contribution to air pollution and climate change has made it increasingly controversial. In everyday use, coal is usually an uncountable mass noun ('the ship was loaded with coal'), while the plural 'coals' denotes individual lumps or glowing fragments in a fire. The word also appears in vivid idioms: to 'haul someone over the coals' is to reprimand them severely, and 'carrying coals to Newcastle' describes a pointless undertaking, since Newcastle upon Tyne was historically synonymous with coal production. Related terms include coal-black, coal-fired, and collier.
A hard black mineral substance consisting mainly of carbon, formed from fossilized plant matter over geological time, used as a fuel; also, a single piece or lump of this substance.
"The power station switched from coal to natural gas in an effort to cut emissions."
Usually uncountable as a bulk substance; the plural 'coals' denotes individual lumps or embers.
To supply (a ship or engine) with coal.
"The steamer put in at Southampton to coal before crossing the Atlantic."
Now dated, used chiefly in historical or nautical contexts.
As a mass noun referring to the substance or industry, coal is normally uncountable; 'coals' appears when speaking of individual lumps or glowing embers, especially in fires.
"He poked at the dying coals in the grate, trying to revive the fire."
Carrying coals to Newcastle means doing something completely pointless — because Newcastle was once so rich in coal that shipping more there would be absurd.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of coal
The word 'coal' comes from Old English 'col', meaning charred or burning material, which traces back through Proto-Germanic '*kulam'. It is related to the German 'Kohle' and Dutch 'kool', all stemming from the same Germanic root. In Middle English the term broadened to cover both charcoal and mineral coal, and by the early modern period it firmly referred to the fossil fuel. Derived English words include 'collier' (a coal miner or coal ship) and the compound 'coal-black', attested since at least the medieval period.
Related word forms
How coal is actually used
Coal is typically uncountable when referring to the substance or industry generally ('the price of coal'); the plural 'coals' refers to individual lumps or glowing embers, often in domestic contexts. The idiom 'carry coals to Newcastle' means to supply something to a place already abundantly supplied with it.
Easily confused with coal
Cole is a plant of the cabbage family (as in cole crops), whereas coal is the black fossil fuel.
Kohl is a dark cosmetic powder used around the eyes, while coal is the combustible black rock.