plural coals
1
: a black or brownish-black hard substance within the earth that is used as a fuel
a bin of coal
The furnace burns coal.
a lump of coal
—often used before another nouna coal bin/mine/bed/stove
the coal industry
2
a
: a piece of coal or charcoal especially when burning
When the coals are red, they are very hot.
b
US
: a glowing piece of wood from a fire : ember
I toasted one last marshmallow over the coals of the campfire.
Cite this Entry
“Coal.” Merriam-Webster.com Simple Definition, Merriam-Webster, https://www.merriam-webster.com/simple/coal. Accessed 21 Jun. 2026.
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