Synonyms and related words :
ageless, ceaseless, changeless, coeternal, constant, continual, continuous, dateless, deathless, durable, endless, enduring, eternal, eterne, ever-being, ever-durable, ever-during, everlasting, everliving, fixed, immemorial, immortal, immutable, imperishable, impregnable, incessant, incorruptible, indelible, ineffaceable, ineradicable, inexpugnable, inextinguishable, infinite, interminable, invincible, invulnerable, irrefragable, lasting, long-lasting, never-ceasing, never-ending, nonperishable, nonstop, nonterminating, nonterminous, olamic, perdurable, perennial, permanent, perpetual, quenchless, sempiternal, steady, timeless, unalterable, unbreakable, unceasing, unchangeable, unchanging, undampable, undestroyable, undying, unending, unintermitting, uninterrupted, unquenchable, unremitting, without end