oxygen

noun, often attributive ox·y·gen \ ˈäk-si-jən \

|Updated on: 13 Aug 2018

Definition of oxygen

1 : a reactive element that is found in water, in most rocks and minerals, in numerous organic compounds, and as a colorless tasteless odorless diatomic gas constituting 21 percent of the atmosphere, that is capable of combining with all elements except the inert gases, that is active in physiological processes, and that is involved especially in combustion — see Chemical Elements Table

2 : something that sustains or fuels

disagreement is the true oxygen of these magazines
—Joseph Epstein

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oxygenless

play \ˈäk-si-jən-ləs\ adjective

See oxygen defined for English-language learners

See oxygen defined for kids

Recent Examples of oxygen from the Web

The relatively low temperature and lack of oxygen in the bag will prevent your pesto from losing its vibrant green color.

— bon appétit, Bon Appetit, "26 Pesto Recipes for When You Want Greens and Cheese," 5 June 2018
The lack of structure that can paralyze most performers was oxygen for them.

— chris nashawaty, WSJ, "How the ‘Caddyshack’ Revolution Upended Hollywood," 19 Apr. 2018
Along with greenhouse gases like carbon dioxide and methane, there's oxygen in our atmosphere.

— National Geographic, "Mudslides, Wildfires, and Drought—California's Deadly Weather Explained," 10 Jan. 2018
Never use candles in the home when there is medical oxygen in use.

— karen pilarski, Milwaukee Journal Sentinel, "Unattended candle might have contributed to Brookfield house fire," 2 Jan. 2018
Well, a 2016 study on 2,000 women suggested that the association between ovarian cancer and talcum powder comes from talc — a mineral made up of magnesium, silicon, and oxygen, that absorbs moisture — not asbestos.

— refinery29.com, "Johnson & Johnson Owes $4.69 Billion In Another Ovarian Cancer Case," 13 July 2018
The light arose from the collision between a remarkably energetic neutrino – a wraithlike subatomic particle moving close to the speed of light – and the nucleus of a hydrogen or oxygen atom deep within the ice.

— eoin o'carroll, The Christian Science Monitor, "Neutrino demonstration heralds a new way of observing the cosmos," 12 July 2018
According to Keeton, these tests indicated his skin sucked in more oxygen than the average human's, causing his body to act as something of a human glue stick.

— elena weissmann, Milwaukee Journal Sentinel, "Meet Kenosha's Jamie 'Can Head' Keeton, the human suction cup," 12 July 2018
Histogen converts the fibroblasts by placing them into simulated embryonic conditions, including suspending them in liquid and low oxygen.

— bradley j. fikes, sandiegouniontribune.com, "Hair regrowth treatment now being tested in women by La Jolla's Histogen," 12 July 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'oxygen.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Origin and Etymology of oxygen

French oxygène, from Greek oxys, adjective, acidic, literally, sharp + French -gène -gen; akin to Latin acer sharp — more at edge

NEW! Time Traveler

First Known Use: 1788

in the meaning defined at sense 1

See Words from the same year

Other Chemical Engineering Terms

alkali, cation, decant, hygroscopic, isotope, oxidize, slurry, solute, viscous

OXYGEN Defined for English Language Learners

oxygen

noun

Definition of oxygen for English Language Learners

: a chemical that is found in the air, that has no color, taste, or smell, and that is necessary for life

OXYGEN Defined for Kids

oxygen

noun ox·y·gen \ ˈäk-si-jən \

Definition of oxygen for Students

: a chemical element found in the air as a colorless odorless tasteless gas that is necessary for life

History for oxygen

People once thought that all acids were formed by adding oxygen to some other substance. This belief turned out not to be true. However, it did give oxygen its name. The first part of the word, oxy-, came from Greek oxys, meaning “acid” or “sharp.” The second part, -gen, came from a Greek element meaning “producing” or “giving rise to.”

Medical Dictionary

oxygen

noun ox·y·gen \ ˈäk-si-jən \

medical Definition of oxygen

: a colorless tasteless odorless gaseous element that constitutes 21 percent of the atmosphere and is found in water, in most rocks and minerals, and in numerous organic compounds, that is capable of combining with all elements except the inert gases, that is active in physiological processes, and that is involved especially in combustion processes —symbol O — see Chemical Elements Table

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