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

Certain bacteria produce methane as they break down organic material, but this only happens when phosphate, an essential nutrient, is in short supply.

From Science Daily • Apr. 16, 2026

Instead of being rare, methane production in oxygen-rich waters may be common in regions where phosphate levels are low.

From Science Daily • Apr. 16, 2026

One reason is the methane is more dispersed and satellites’ sensors have trouble picking it out over a large area.

From Los Angeles Times • Apr. 15, 2026

Estimating methane from a reservoir is trickier than measuring plumes from natural gas wells or landfills, scientists say.

From Los Angeles Times • Apr. 15, 2026

We mix together and spark the gases of the primitive Earth: hydrogen, water, ammonia, methane, hydrogen sulfide—all present, incidentally, on the planet Jupiter today and throughout the Cosmos.

From "Cosmos" by Carl Sagan