methane

American  

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

noun

Chemistry.

methanes plural

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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Other Word Forms

Noun Inflected Forms

• methanes
  plural

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 is the single fastest lever we have to limit near-term warming. We can no longer wait to pull this lever," he added.

From Barron's • May 4, 2026

Methane levels remained steady at about 500 parts per billion.

From Science Daily • Apr. 24, 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, the second-biggest contributor to climate change, is spewing into the atmosphere from the oil and gas industry, landfills and dairy farms.

From Los Angeles Times • Apr. 15, 2026

Methane, meth′ān, n. marsh-gas, the simplest hydrocarbon, found wherever the decomposition of vegetable matter is taking place under water, also in coal-mines, forming when mixed with air the deadly fire-damp.—n.

From Chambers's Twentieth Century Dictionary (part 2 of 4: E-M) by Various