# heavy hydrogen

> English word · Noun

## Definitions
1. Synonym of deuterium.

## Etymology
An atom of said isotope weighs about 2 daltons, about twice as much as an atom of light hydrogen.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/heavy-hydrogen