miasma

American  

[mahy-az-muh, mee-] / maɪˈæz mə, mi- /

noun

miasmas, plural miasmata plural

1. noxious exhalations from putrescent organic matter; poisonous effluvia or germs polluting the atmosphere.

2. a dangerous, foreboding, or deathlike influence or atmosphere.

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miasma British  

/ mɪˈæzmə, ˌmiːəzˈmætɪk /

noun

1. an unwholesome or oppressive atmosphere

2. pollution in the atmosphere, esp noxious vapours from decomposing organic matter

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Other Word Forms

Derived Forms

• miasmal
  adjective
• miasmatic
  adjective
• miasmatical
  adjective
• miasmic
  adjective
• unmiasmal
  adjective
• unmiasmatic
  adjective
• unmiasmatical
  adjective
• unmiasmic
  adjective

Inflected Forms

Nouns

• miasmas
  plural
• miasmata
  plural

Etymology

Origin of miasma

1655–65; < New Latin < Greek míasma stain, pollution, akin to miaínein to pollute, stain

Explanation

A miasma is a cloud of foul-smelling vapor, like swamp gas. You could have a miasma of sweat that lingers in a locker room long after a soccer team has left, or a miasma of rumor swirling around a politician. As you've probably figured out, miasma is always negative. You could describe the miasma of a hot summer day, but you'd be thinking of the stench of uncollected garbage and exhaust fumes, not the smell of summer flowers. From the Middle Ages until the late 19th century, when germs were identified as causing disease, people believed that you could get sick from the miasma of everyday life — from the odors arising from poor sanitation and cramped quarters.

Example Sentences

See Examples For:

miasma miasmas miasmata

There’s some truth to this, but the overarching emphasis on miasma theory fundamentally ignores how the immune system works.

From Salon ● Nov. 29, 2025

Few writers since Henry James can create an atmosphere of doubt around events and character as effectively as this author does, and in “Venetian Vespers” the miasma thickens at every turn.

From The Wall Street Journal ● Oct. 9, 2025

It was a couple of weeks after the great smog had brought London to a standstill, and although that particularly foul miasma had dispersed, smog still regularly reduced visibility.

From BBC ● Dec. 30, 2024

This miasma of mockery and admiration is relevant again to the actor because of the unexpected viral notoriety of his character in “Dream Scenario.”

From Los Angeles Times ● Jan. 2, 2024

The medical community believed the illness was caused by foul air, called miasma, rising from wet areas.

From "Ambushed!" by Gail Jarrow

It’s also possible the miasmas of their lives and interests will swirl off in other directions for any number of other reasons independent of how they feel about each other.

From Washington Post ● Aug. 27, 2021

Modern warfare creates miasmas of emotion, information, misinformation, deception and secrecy.

From The Guardian ● Sep. 8, 2018

It was not difficult, then, to accept the idea that foul-smelling toilets, drains, and the huge piles of horse manure that lined city streets harbored dangerous bacteria instead of miasmas.

From Salon ● May 21, 2012

Soon germs became even more frightening than miasmas.

From Salon ● May 21, 2012

Yet the horror and reek of those two days in the miasmas still clung in his memory, even in his nostrils, he sometimes imagined.

From Caravans By Night A Romance of India by Hervey, Harry

At this point, the atmosphere is loaded with pestilential miasmata.

From Life and Travels of Mungo Park in Central Africa by Park, Mungo

Mange exerts a morbid constitutional action on the skin; it is infectious from various miasmata, and it is contagious from personal communication.

From The Dog by Youatt, William

The miasmata appear to ascend until they reach the level of the town above, where the atmosphere being less dense, and perhaps precisely of their own specific gravity, they float, and commingle with it.

From A Ramble of Six Thousand Miles through the United States of America by Ferrall, S. A. (Simon Ansley)

Injurious as are the miasmata in general, and fatal as are the effects of that peculiar form in this country, termed malaria; the diseases they engender, I apprehend to be rather endemic than epidemic.

From A Love Story by A Bushman

Ancient philosophers seem to have believed, that the contagious miasmata in their warm climates affected horses and dogs previous to mankind.

From Zoonomia, Vol. II Or, the Laws of Organic Life by Darwin, Erasmus