An odorless, colorless, flammable gas, CH4, the major constituent of natural gas, that is used as a fuel and is an important source of hydrogen and a wide variety of organic compounds.

• 甲烷一种无味，无色，易燃汽体，CH4，是天然气的主要组成部分，被用作燃料，是氢和其它多种有机化合物的重要来源