deuterium

https://doi.org/10.1351/goldbook.D01648
A specific name for the atom $\ce{^{2}H}$. The cation $\ce{2H^{+}}$ is a deuteron the species $\ce{2H^{−}}$ is a 'deuteride' anion and $\ce{^{2}H}$ is the 'deuterio' group.
Source:
PAC, 1988, 60, 1115. (Names for hydrogen atoms, ions, and groups, and for reactions involving them (Recommendations 1988)) on page 1116 [Terms] [Paper]