The term "hot coal" is commonly used to describe a piece of fuel that is burning red-hot and glowing. There are several synonyms for the phrase, such as ember, cinder, and live coal. These words are usually interchangeably used to describe firewood that has been burnt and reduced to ashes. Another synonym for hot coal is kindling, which refers to small pieces of wood or other easily combustible materials used to start a fire. In some cases, the term furnace or hearth can also describe a hot coal as it pertains to the fire's location or source.