An adjective referring to psions (see psions), to the powers or energies based on psions (e.g., psionic powers, psionic energy), or to mechanical means to stimulate the natural psi powers. Abbreviated to psi only when describing the powers.

In the television show Mutant X Genomex created four classes of new mutants: elemental, feral, molecular and psionic. Psionic new mutants are very powerful. They focus their powers through their minds and it is not uncommon for one psionic to have powers belonging to several subclasses.

Pertaining to the most mental manipulation of the hypothetical subatomic particles called psions.