oxygen
a colorless, odorless, gaseous element constituting about one-fifth of the volume of the atmosphere and present in a combined state in nature. It is the supporter of combustion in air and was the standard of atomic, combining, and molecular weights until 1961, when carbon 12 became the new standard. Symbol: O; atomic weight: 15.9994; atomic number: 8; density: 1.4290 grams/liter at 0°C and 760 millimeter pressure.
Origin of oxygen
1Other words from oxygen
- ox·y·gen·ic [ok-si-jen-ik], /ˌɒk sɪˈdʒɛn ɪk/, ox·yg·e·nous [ok-sij-uh-nuhs], /ɒkˈsɪdʒ ə nəs/, adjective
- ox·y·gen·ic·i·ty [ok-si-juh-nis-i-tee], /ˌɒk sɪ dʒəˈnɪs ɪ ti/, noun
Words Nearby oxygen
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
How to use oxygen in a sentence
Most carbohydrates have the same oxygen to hydrogen ratio as water.
Her aunt eventually recovered, was taken off a ventilator and is home, though she still needs oxygen.
Coronavirus Hit Latinos Harder Thanks to a Perfect Storm of Disparities | Maya Srikrishnan | August 12, 2020 | Voice of San DiegoPhotosynthetic cyanobacteria that arose some 3 billion years ago, for instance, began terraforming the planet by emitting oxygen.
How Earth’s Climate Changes Naturally (and Why Things Are Different Now) | Howard Lee | July 21, 2020 | Quanta MagazineResearchers found no benefit for hospitalized patients who didn’t need extra oxygen.
The steroid dexamethasone is the first drug shown to reduce COVID-19 deaths | Tina Hesman Saey | June 16, 2020 | Science NewsSo extra oxygen in the atmosphere may have provided the conditions for large insects to evolve.
Minecraft’s big bees don’t exist, but giant insects once did | Carolyn Wilke | May 14, 2020 | Science News For Students
The others are difficult to identify, since they reacted with other oxygen-bearing molecules in the soil.
It reacts very readily with oxygen by burning smokelessly, with carbon dioxide and water as its byproducts.
Their decay proceeded without a ready supply of oxygen, producing hydrocarbons like methane instead of oxygen-bearing molecules.
As the heart pumps blood to the far reaches of the body, it requires its own blood flow to receive vital oxygen and nutrients.
Justice Ruth Bader Ginsburg’s Risky Heart Surgery | Dr. Anand Veeravagu, MD | November 26, 2014 | THE DAILY BEASTThe brain, also an organ, is particularly sensitive to the loss of oxygen.
What It’s Like to Wake Up Dead | Dr. Anand Veeravagu, MD, Tej Azad | November 21, 2014 | THE DAILY BEASTIn the lungs hemoglobin forms a loose combination with oxygen, which it readily gives up when it reaches the tissues.
A Manual of Clinical Diagnosis | James Campbell ToddThey are cells which have been highly differentiated for the purpose of carrying oxygen from the lungs to the tissues.
A Manual of Clinical Diagnosis | James Campbell ToddIts most important compound is water, of which it forms one-ninth, the other eight-ninths consisting of oxygen.
Elements of Agricultural Chemistry | Thomas AndersonIn the flowers, both by day and night, there is a constant absorption of oxygen, and evolution of carbonic acid.
Elements of Agricultural Chemistry | Thomas AndersonIn the first case, the oil rapidly combines with the oxygen of the air, this being accompanied by great heat.
The Wonder Book of Knowledge | Various
British Dictionary definitions for oxygen
/ (ˈɒksɪdʒən) /
a colourless odourless highly reactive gaseous element: the most abundant element in the earth's crust (49.2 per cent). It is essential for aerobic respiration and almost all combustion and is widely used in industry. Symbol: O; atomic no: 8; atomic wt: 15.9994; valency: 2; density: 1.429 kg/m³; melting pt: –218.79°C; boiling pt: –182.97°C
(as modifier): an oxygen mask
Derived forms of oxygen
- oxygenic (ˌɒksɪˈdʒɛnɪk) or oxygenous (ɒkˈsɪdʒɪnəs), adjective
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
Scientific definitions for oxygen
[ ŏk′sĭ-jən ]
A nonmetallic element that exists in its free form as a colorless, odorless gas and makes up about 21 percent of the Earth's atmosphere. It is the most abundant element in the Earth's crust and occurs in many compounds, including water, carbon dioxide, and iron ore. Oxygen combines with most elements, is required for combustion, and is essential for life in most organisms. Atomic number 8; atomic weight 15.9994; melting point -218.8°C; boiling point -182.9°C; gas density at 0°C 1.429 grams per liter; valence 2. See Periodic Table.
word history
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Cultural definitions for oxygen
Notes for oxygen
Notes for oxygen
The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
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