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.

---

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

---

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 .

---

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

This is unexpected because methane is usually produced in environments that lack oxygen, such as wetlands or deep ocean sediments.

From Science Daily • Apr. 16, 2026

These findings reshape how scientists think about methane in the ocean.

From Science Daily • Apr. 16, 2026

How much planet-warming methane is coming from water reservoirs?

From Los Angeles Times • Apr. 16, 2026

As plants break down underwater, they form methane, which then bubbles to the surface.

From Los Angeles Times • Apr. 15, 2026

When Earth was only about a third of its eventual size, it was probably already beginning to form an atmosphere, mostly of carbon dioxide, nitrogen, methane, and sulfur.

From "A Short History of Nearly Everything" by Bill Bryson