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

noun Chemistry.

a colorless, odorless, flammable gas, CH4, 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.

Nearby words

  1. methaemoglobin,
  2. methamphetamine,
  3. methamphetamine hydrochloride,
  4. methanal,
  5. methanation,
  6. methane series,
  7. methanesulfonic acid,
  8. methanogen,
  9. methanoic acid,
  10. methanol

Origin of methane

First recorded in 1865–70; meth- + -ane Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for methane

British Dictionary definitions for methane


/ (ˈmiːθeɪn) /


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

Word Origin for methane

C19: from meth (yl) + -ane

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for methane



"inflammable colorless and odorless gas, marsh gas," 1867, coined from methyl + chemical suffix -ane.

Online Etymology Dictionary, © 2010 Douglas Harper

Medicine definitions for methane


[ mĕthān′ ]


An odorless, colorless, flammable gas that is the major constituent of natural gas and is used as a fuel and as an important source of hydrogen.marsh gas

The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Science definitions for methane


[ mĕthān′ ]

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: CH4.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.