1. A piece of wood, or other combustible substance, ignited, burning, or charred. When burning or ignited, it is called a live coal or burning coal or coal of fire. When the fire is extinct, it is called charcoal.
2. In the language of chimists, any substance containing oil, which has been exposed to a fire in a close vessel, so that its volatile matter is expelled, and it can sustain a red heat without further decomposition.
3. In mineralogy, a solid, opake, inflammable substance, found in the earth, and by way of distinction called fossil coal It is divided by recent mineralogists into three species, anthracite or glance coal black or bituminous coal and brown coal or lignite; under which are included many varieties, such as cannel coal bovey coal jet, etc.
COAL, verb transitive
1. To burn to coal or charcoal; to char.
2. To mark or delineate with charcoal.