|a gaseous mixture consisting mainly of methane trapped below ground; used extensively as a fuel|
|natural gas (nāch'ər-əl) Pronunciation Key
A mixture of hydrocarbon gases that occurs naturally beneath the Earth's surface, often with or near petroleum deposits. Natural gas contains mostly of methane but also has varying amounts of ethane, propane, butane, and nitrogen. It is used as a fuel and in making organic compounds.