Definition of oxygen in English:

Share this entry


Pronunciation: /ˈäksəjən/


A colorless, odorless reactive gas, the chemical element of atomic number 8 and the life-supporting component of the air. Oxygen forms about 20 percent of the earth’s atmosphere, and is the most abundant element in the earth’s crust, mainly in the form of oxides, silicates, and carbonates. (Symbol: O)
Example sentences
  • Energy is generated by the reaction of hydrogen and oxygen across a catalytic membrane.
  • Solar panels power an electrolyser that separates water into hydrogen and oxygen.
  • In addition, the very reactive singlet oxygen can be generated by an input of energy.



Pronunciation: /äkˈsijənəs/
Example sentences
  • A process for separating oxygenous organic compounds from aqueous media by liquid-liquid extraction with an organic extraction agent.
  • In the case of distillation columns or in the case of reactors, these oxygenous gases are generally metered into the bottom, for example into the bottom circuit.


Late 18th century: from French (principe) oxygène 'acidifying constituent' (because at first it was held to be the essential component in the formation of acids).

For editors and proofreaders

Syllabification: ox·y·gen

Share this entry

What do you find interesting about this word or phrase?

Comments that don't adhere to our Community Guidelines may be moderated or removed.