oxygen

noun

Etymology: Etymology tree Proto-Indo-European *h₂eḱ-der.? Ancient Greek ὀξύς (oxús) Proto-Indo-European *ǵenh₁- Proto-Indo-European *-os Proto-Indo-European *ǵénh₁os Proto-Hellenic *génos Ancient Greek γένος (génos) French oxygènebor. English oxygen Borrowed from French oxygène (originally in the form principe oxygène, a variant of principe oxigine ‘acidifying principle’, suggested by Lavoisier), from Ancient Greek ὀξύς (oxús, “sharp”) + γένος (génos, “birth”), referring to oxygen's supposed role in the formation of acids. By surface analysis, oxy- + -gen.

1. The chemical element (symbol O) with an atomic number of 8 and relative atomic mass of 15.9994. It is a colorless and odorless gas. Sometimes called elemental oxygen to distinguish it from molecular oxygen.

   “Holonyms: dioxygen, O₂, oxygen (loose sense)”

   “By molar fraction, calcium oxide contains equal parts calcium and oxygen.”

2. Molecular oxygen (O₂), a colorless, odorless gas at room temperature.

   “Meronym: oxygen (strict sense)”

   “About 21% of the air you breathe is oxygen.”

3. A mixture of oxygen and other gases, administered to a patient to help them breathe.
4. An atom of this element.

   “Look first at any structure to see if there is a carbon with two oxygens attached. Hemiacetals, hemiketals, acetals, and ketals are all alike in that regard.”

5. A condition or environment in which something can thrive.

   “Silence is the oxygen of shame.”

   “They hoped to starve the terrorists of the oxygen of publicity.”