Natural gas

Underground deposits of gases consisting of 50 to 90 percent methane (CH4) and small amounts of heavier gaseous hydrocarbon compounds such as propane (C3H8) and butane (C4H10).

Underground deposits of gases consisting of 50 to 90 percent methane (CH₄) and small amounts of heavier gaseous hydrocarbon compounds such as propane (C_{3 8}) and butane (C_{4 10}).

A hydrocarbon gas obtained from underground sources, often in association with petroleum and coal deposits. It generally contains a high percentage of methane, varying amounts of ethane, and inert gases; used as a heating fuel.

A naturally occurring combustible mixture of gases recovered from the earth from wells. It is composed predominantly of methane, but contains other light hydrocarbons and impurities.

A mixture of gaseous hydrocarbons, primarily methane, occurring naturally in the earth. Used as fuel.