The Oxford Thesaurus An A-Z Dictionary of Synonyms - eternal adj.

1) everlasting, timeless, infinite, endless, immortal, limitless: They pledged eternal love for one another. 2) unending, endless, ceaseless, unceasing, incessant, perpetual, constant, continuous, interminable, uninterrupted, non-stop, unremitting, persistent, relentless; continual, recurrent: I'm sick and tired of my neighbours' eternal arguing. 3) unchanged, unchanging, immutable, invariable, unvarying, unalterable, permanent, fixed, constant, everlasting, enduring, lasting, undiminished, unfaltering, unwavering: To the north there was only the eternal silence of the greatest desolation.