A hydrocarbon-based fuel, such as petroleum, coal, or natural gas, derived from living matter of a previous geologic time.
An organic substance, as coal, petroleum, etc., found underground in deposits formed in a previous geologic period and used as a source of energy.
A hydrocarbon fuel, such as petroleum, coal, or natural gas, derived from the accumulated remains of ancient plants and animals and used as fuel. Carbon dioxide and other greenhouse gases generated by burning fossil fuels are considered to be one of the principal causes of global warming.
The definition of fossil fuel is an organic substance from the geologic period which is found underground and is used as a source of energy.
An example of a fossil fuel is coal.