marsh gas

noun

1. a gaseous decomposition product of organic matter, consisting primarily of methane.

marsh gas

noun

1. a hydrocarbon gas largely composed of methane formed when organic material decays in the absence of air

Word History and Origins

Origin of marsh gas¹

An Americanism dating back to 1775–85

Example Sentences

I don’t read Swedish, so I’m unsure how to apportion credit for beautiful sentences, but they abound: Snide comments are “tiny puffs of marsh gas.”

From New York Times

The layer of muck had small holes all over it, where marsh gas breathed out.

From Literature

This ‘marsh gas’ is methane, a greenhouse gas that is some 20 times more potent than carbon dioxide.

From Nature

The simplest of these is methane, or marsh gas, which is formed in nature by the bacterial decomposition of organic matter under water.

From The New Yorker

It was subject to continual leaks and floods, and suffused with fetid marsh gases that would periodically combust, ignited by the gas lamps that lit the tunnel.

From The New Yorker