methane

American  

[meth-eyn, mee-theyn] / ˈmɛθ eɪn, ˈmi θeɪn /

noun

Chemistry.

1. a colorless, odorless, flammable gas, CH 4 , the main constituent of marsh gas and the firedamp of coal mines, obtained commercially from natural gas: the first member of the methane, or alkane, series of hydrocarbons.

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methane British  

/ ˈmiːθeɪn /

noun

1. a colourless odourless flammable gas, the simplest alkane and the main constituent of natural gas: used as a fuel. Formula: CH 4 See also marsh gas firedamp

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methane Scientific  

/ mĕth′ān′ /

1. A colorless, odorless, flammable gas that is the simplest hydrocarbon. It is the major constituent of natural gas and is released during the decomposition of plant or other organic compounds, as in marshes and coal mines. Methane is the first member of the alkane series. Chemical formula: CH ₄ .

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Etymology

Origin of methane

First recorded in 1865–70; meth- + -ane

Explanation

Methane, a colorless, odorless gas that occurs naturally on Earth, is a component in natural gas. It's also one of the major contributors to climate change. Methane is highly flammable, and it comprises as much as 90 percent of the natural gas that's commonly used for heating, cooking, and generating electricity. Although the release of methane into the atmosphere is a natural process, too much of it contributes to the greenhouse effect, trapping heat in the atmosphere and warming the planet. Methane was discovered by an Italian scientist in 1776, who collected the gas as it rose from a marsh.

Example Sentences

Methane, the second biggest contributor to climate change, stays in the atmosphere for far less time than carbon dioxide, but its warming effect is roughly 80 times more potent over a 20-year period.

From Barron's • May 4, 2026

Methane and oxygen, for example, would normally react with each other, forming carbon dioxide and water.

From The Wall Street Journal • Apr. 23, 2026

Methane is roughly 80 times more potent than carbon dioxide as a greenhouse gas over a 20-year horizon.

From MarketWatch • Jan. 21, 2026

Methane forms lakes on Titan and even falls from the sky as rain.

From Science Daily • Dec. 20, 2025

The mountain of Methane, on the coast of Argolis, was produced by a volcanic eruption in 282 B.C.

From Encyclopaedia Britannica, 11th Edition, Volume 12, Slice 4 "Grasshopper" to "Greek Language" by Various