Definitions for "Fossil fuel"
substances derived from the decomposition of prehistoric plants and animals that can be burned to produce energy (i.e., coal, oil, and natural gas).
Burnable chemicals that are the resulting remains of prehistoric animals and plants. Carbon based remains of organic matter geologically transformed into coal , oil, and natural gas.
coal, petroleum, or natural gas; consists of carbon-based molecules derived from decomposition of once-living organisms
Keywords:  reservoir, rock
Reservoir Rock