(a.) Not commutable; not capable of being exchanged with, or substituted for, another.
Thesaurus Entries
changeless, constant, immutable, inconvertible, indefeasible, inert, insusceptible of change, intransmutable, invariable, irretrievable, irreversible, irrevocable, lasting, noble, nonreturnable, nonreversible, permanent, reverseless, unalterable, unalterative, unaltered, unchangeable, unchanged, unchanging, undeflectable, undeviating, unmodifiable, unremitting, unrestorable, unreturnable, unsusceptible, unvariable, unvarying
