List of unalterable synonyms and unalterable related words.
adamant, adamantine, cast-iron, changeless, constant, dour, firm, fixed, flinty, grim, hard, hard-core, immovable, immutable, implacable, impliable, inalterable, incommutable, inconvertible, indefeasible, inductile, inelastic, inert, inexorable, inextensible, inextensile, inextensional, inflexible, insusceptible of change, intractable, intractile, intransigent, intransmutable, invariable, iron, irreconcilable, irresilient, irretrievable, irreversible, irrevocable, lasting, noble, nonelastic, nonreturnable, nonreversible, nonstretchable, permanent, relentless, reverseless, rigid, rigorous, rock-ribbed, steely, stern, stiff, stubborn, unaffected, unalterative, unaltered, unbending, unchangeable, unchanged, unchanging, uncompromising, undeflectable, undeviating, unextendible, unextensible, unflexible, ungiving, unlimber, unmalleable, unmodifiable, unmovable, unmoved, unpliable, unpliant, unrelenting, unremitting, unrestorable, unreturnable, unsusceptible, untractable, unvariable, unvarying, unyielding