English · Word Candidate

hydrogen

/ˈhaɪdɹəd͡ʒ(ə)n/

Proposed by a contributor, not yet supported by evidence.

Also seen as: hydrogens

Sense 1

Meaning · English

The lightest chemical element (symbol H), with an atomic number of 1 and atomic weight of 1.008.

Noun

Examples

Our professor then reminded us that a hydrogen ion is merely a proton, and thus we should think about acid-base theory as we consider this problem further.

Usage example from English Wiktionary (CC BY-SA 4.0, retrieved 2026-08-01)

Sources & notes

Adapted from English Wiktionary (CC BY-SA 4.0, retrieved 2026-08-01 via kaikki.org).

Sense 2

Meaning · English

The lightest chemical element (symbol H), with an atomic number of 1 and atomic weight of 1.008. — An atom of this element.

Noun

Examples

Each carbon of the ring has one hydrogen attached except for the fourth one, which is bonded to a substituent.

Usage example from English Wiktionary (CC BY-SA 4.0, retrieved 2026-08-01)

Sources & notes

Adapted from English Wiktionary (CC BY-SA 4.0, retrieved 2026-08-01 via kaikki.org).

Common questions

What does “hydrogen” mean?

The lightest chemical element (symbol H), with an atomic number of 1 and atomic weight of 1.008.

Is “hydrogen” formal or informal?

No register label has been reviewed yet — treat it as neutral and check the usage notes above.