H2O

Cultural  

1. The chemical symbol (see also symbol) for water. Each molecule of water contains two atoms of hydrogen (H) joined to a single atom of oxygen (O).

---

Example Sentences

"If we're going to send humans to Mars, you need H2O and not just for drinking, but for propellant and all manner of applications," Luzzi said.

From Science Daily • Dec. 27, 2025

H2O is the stuff of life, but for several decades, water producers and sommeliers have been working to make it something more: the stuff of taste.

From The Wall Street Journal • Oct. 20, 2025

Here, at depths of 5km, where no sunlight can penetrate, the oxygen appears to be produced by naturally occurring metallic “nodules” which split seawater - H2O - into hydrogen and oxygen.

From BBC • Jul. 22, 2024

The business of boosting one’s H2O is projected to reach $3.26 billion by 2031.

From Los Angeles Times • Jul. 22, 2024

Later, for no special reason, the fashion became to render the number as subscript: H2O.

From "A Short History of Nearly Everything" by Bill Bryson

Related Words

• drink
• rain