methane

noun

meth·​ane ˈme-ˌthān How to pronounce methane (audio)
British usually ˈmē-
: a colorless odorless flammable gaseous hydrocarbon CH4 that is a product of biological decomposition of organic matter and of the carbonization of coal, is used as a fuel and as a starting material in chemical synthesis, and is the simplest of the alkanes

Examples of methane in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
The timing of the snow and ice melt, plus rainfalls, determines whether a plot of thawing permafrost is waterlogged — and whether carbon isn’t just turned into CO2, but also methane, a greenhouse gas four times as potent. — Denise Hruby, Miami Herald, 31 July 2026 The bodies of the six miners were recovered hours after the deadly blast, apparently triggered by a buildup of methane gas, Baloch said. — ABC News, 30 July 2026 Carbon dioxide and methane levels in the samples prove these organisms then began feeding on the shale itself. — Andrew Paul, Popular Science, 29 July 2026 In experiments, wiping out protozoans allowed bacteria to grow exponentially, which generated more hydrogen and more methane, Mackie said. — Marlowe Starling, Quanta Magazine, 27 July 2026 See All Example Sentences for methane

Word History

Etymology

International Scientific Vocabulary

First Known Use

1867, in the meaning defined above

Time Traveler
The first known use of methane was in 1867

Rhymes for methane

See All Rhymes for methane

Browse Nearby Words

methanation
methane
methanesulfonic acid
See all Nearby Words

Cite this Entry

“Methane.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/methane. Accessed 1 Aug. 2026.

Copy Citation

Kids Definition

methane

noun
meth·​ane ˈmeth-ˌān How to pronounce methane (audio)
: a colorless odorless flammable gas that consists of carbon and hydrogen and is produced by decay of organic matter

Medical Definition

methane

noun
meth·​ane
ˈmeth-ˌān, British usually ˈmē-ˌthān
: a colorless, odorless, flammable, gaseous hydrocarbon CH4 that is lighter than air, forms explosive mixtures with air or oxygen, and occurs naturally as a by-product of the decomposition of organic matter by anaerobic bacteria

called also marsh gas

More from Merriam-Webster on methane

Nglish: Translation of methane for Spanish Speakers

Britannica.com: Encyclopedia article about methane

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

More from Merriam-Webster

Word of the Day

Listen to the pronunciation of spindrift

See Definitions and Examples »

Popular in Grammar & Usage

See More

7 Pairs of Commonly Confused Words

Merriam-Webster’s Great Big List of Words You Love to Hate

Is it 'nerve-racking' or 'nerve-wracking'?

Why does English have so many silent letters?

Your vs. You're: How to Use Them Correctly
See More

Popular in Wordplay

See More

Dutch Treat and French Leave: Eight Place-Based Compounds

14 Phobias You Probably Haven't Heard Of

The Longest Long Words List

The Words of the Week - Jul. 31

Even More Bird Names that Sound Like Insults (and Sometimes Are)
See More

Popular

See More

7 Pairs of Commonly Confused Words

Dutch Treat and French Leave: Eight Place-Based Compounds

14 Phobias You Probably Haven't Heard Of
See More

Games & Quizzes

See All
Play Quordle: Guess all four words in a limited number of tries. Each of your guesses must be a real 5-letter word.
Quordle Can you solve 4 words at once?
Play Blossom: Solve today's spelling word game by finding as many words as you can using just 7 letters. Longer words score more points.
Blossom Pick the best words!
Play Missing Letter: a crossword with a twist. Each of the 25 puzzle words start with a different letter of the alphabet. Which letter is missing?
The Missing Letter A daily crossword with a twist
asap street sign
Figure Out These Acronyms ASAP You don't have to be a NASA engineer to get these...
See All