abiding changeless constant continuing durable enduring firm fixed frozen immobile immutable incommutable inconvertible indefeasible inert insusceptible of change intact intransmutable invariable inviolate irretrievable irreversible irrevocable lasting noble nonreturnable nonreversible permanent perpetual persistent quiescent remaining reverseless rigid solid stable static stationary staying steadfast sustained torpid unalterable unalterative unchangeable unchanged unchanging unchecked undeflectable undestroyed undeviating unfading unfailing unmodifiable unremitting unrestorable unreturnable unshifting unsusceptible unvariable unvaried unvarying