tritium

also defines: tritide, tritio, triton
https://doi.org/10.1351/goldbook.T06513
A specific name for the atom $\ce{^{3}H}$. The cation $\ce{^{3}H^{+}}$ is a triton, the species $\ce{^{3}H^{−}}$ is a tritide anion and $\ce{^{3}H}$ is the tritio 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]