noun, often attributive \ˈkōl\

: a black or brownish-black hard substance within the earth that is used as a fuel

: a piece of coal or charcoal especially when burning

: a glowing piece of wood from a fire

Full Definition of COAL

:  a piece of glowing carbon or charred wood :  ember
:  charcoal 1
a :  a black or brownish-black solid combustible substance formed by the partial decomposition of vegetable matter without free access of air and under the influence of moisture and often increased pressure and temperature that is widely used as a natural fuel
b plural British :  pieces or a quantity of the fuel broken up for burning

Examples of COAL

  1. When the coals are red, they are very hot.
  2. I toasted one last marshmallow over the coals of the campfire.

Origin of COAL

Middle English col, from Old English; akin to Old High German & Old Norse kol burning ember, Middle Irish gúal coal
First Known Use: before 12th century

Other Geology Terms

anthracite, boulder, cwm, erratic, igneous, intrusive, mesa, sedimentary, silt, swale



Definition of COAL

transitive verb
:  to burn to charcoal :  char
:  to supply with coal
intransitive verb
:  to take in coal

First Known Use of COAL



noun    (Concise Encyclopedia)

Solid, usually black but sometimes brown, carbon-rich material that occurs in stratified sedimentary deposits. One of the most important fossil fuels, it is found in many parts of the world. Coal is formed by heat and pressure over millions of years on vegetation deposited in ancient shallow swamps (see peat). It varies in density, porosity, hardness, and reflectivity. The major types are lignite, subbituminous, bituminous, and anthracite. Coal has long been used as fuel, for power generation, for the production of coke, and as a source of various compounds used in synthesizing dyes, solvents, and drugs. The search for alternative energy sources has periodically revived interest in the conversion of coal into liquid fuels; technologies for coal liquefaction have been known since early in the 20th century.


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