Definitions for oxygenˈɒk sɪ dʒən

Random House Webster's College Dictionary

ox•y•genˈɒk sɪ dʒən(n.)

a colorless, odorless, gaseous element constituting about one-fifth of the volume of the atmosphere and present in a combined state in nature. Symbol: O; at. wt.: 15.9994; at. no.: 8; density: 1.4290 g/l at 0°C and 760 mm pressure.
Category: Chemistry

Origin of oxygen:

1780–90; < F oxygène (1786), short for principe oxygène acidifying principle; see oxy -1, -gen

ox`y•gen′ic-ˈdʒɛn ɪk; -ˈsɪdʒ ə nəs(adj.)ox•yg′e•nous

Princeton's WordNet

oxygen, O, atomic number 8(noun)
a nonmetallic bivalent element that is normally a colorless odorless tasteless nonflammable diatomic gas; constitutes 21 percent of the atmosphere by volume; the most abundant element in the earth's crust

Kernerman English Learner's Dictionary

oxygen(noun)ˈɒk sɪ dʒən
a chemical element found in air that is necessary for breathing

Wiktionary

oxygen(Noun)
A chemical element (symbol O) with an atomic number of 8 and relative atomic mass of 15.9994.
oxygen(Noun)
Molecular oxygen (O), a colorless, odorless gas at room temperature.
oxygen(Noun)
A mixture of oxygen and other gases, administered to a patient to help him or her to breathe.
oxygen(Noun)
An atom of this element.

Origin: Borrowed from oxygène (originally in the form principe oxygène, a variant of principe oxigine ‘acidifying principle’, suggested by Lavoisier), from ὀξύς + γένος, referring to oxygen's role in the formation of acids.

The Nuttall Encyclopedia

Oxygen
a colourless, inodorous gas which constitutes one-fifth in volume of the atmosphere, and which, in combination with hydrogen, forms water. It is the most widely diffused of all the elementary bodies, and an essential support to everything possessed of life.

U.S. National Library of Medicine

Oxygen
An element with atomic symbol O, atomic number 8, and atomic weight 16. It is the most abundant element on earth and essential for respiration.