protium

Also contains definitions of: protide, protio

A specific name for the atom 1H. The cation1H+ is a proton, the species 1H is a protide anion, and 1H is the protio group. The word proton should not be used for H+ in its natural abundance.
Source:
PAC, 1988, 60, 1115 (Names for hydrogen atoms, ions, and groups, and for reactions involving them (Recommendations 1988)) on page 1116