THESAURUS
perdurable
abiding, age-long, aged, ageless, ancient, antique, ceaseless, chronic, coeternal, constant, continual, continuing, continuous, dateless, diuturnal, durable, endless, enduring, eternal, eterne, ever-being, ever-durable, ever-during, evergreen, everlasting, everliving, hardy, illimitable, immemorial, immutable, incessant, indestructible, infinite, interminable, intransient, inveterate, lasting, long-lasting, long-lived, long-standing, long-term, longeval, longevous, macrobiotic, never-ceasing, never-ending, nonstop, nonterminating, nonterminous, of long duration, of long standing, olamic, perduring, perennial, permanent, perpetual, persistent, persisting, remaining, sempervirent, sempiternal, stable, staying, steadfast, steady, timeless, tough, unceasing, unending, unfading, unintermitting, uninterrupted, unremitting, vital, without end