■ noun the chemical element of atomic number 8, a colourless, odourless reactive gas that forms about 20 per cent of the earth's atmosphere and is essential to plant and animal life. (Symbol: O )
Derivatives
~ic adjective
~ous adjective
Origin
C18: from Fr. (principe) oxygène 'acidifying constituent' (because at first it was held to be the essential component of acids).