Synonyms and related words :
Spartan, abiding, accepting, adamantine, age-long, aged, alive, ancient, antique, armed with patience, assiduous, bulky, changeless, chronic, constant, continuing, dense, diligent, disciplined, diuturnal, dogged, durable, eidetic, endurant, eternal, evergreen, faithful, firm, fixed, forbearing, fresh, frozen, green, hard, hardy, heavy, immobile, immortal, immutable, inalterable, indefatigable, indomitable, indulgent, industrious, insistent, intact, intransient, inveterate, invincible, inviolate, kept in remembrance, lasting, lenient, long-lasting, long-lived, long-standing, long-suffering, long-term, longanimous, longeval, longevous, loyal, macrobiotic, massive, never-tiring, obstinate, of long duration, of long standing, patient, patient as Job, perdurable, perduring, perennial, permanent, perpetual, perseverant, persevering, persistent, persisting, pertinacious, philosophical, plodding, plugging, preoccupied, quiescent, rapt, recalled, recollected, relentless, remaining, remembered, resolute, retained, rigid, rugged, sedulous, self-controlled, sempervirent, single-minded, sleepless, slogging, solid, sound, stable, static, stationary, staying, steadfast, steady, stoic, stout, strong, stubborn, sturdy, sustained, tenacious, tireless, tolerant, tolerating, tolerative, torpid, tough, unabating, unaltered, unchangeable, unchanged, unchanging, unchecked, unconquerable, undaunted, understanding, undestroyed, undiscouraged, undrooping, unfading, unfailing, unfaltering, unflagging, unflinching, unforgotten, unintermitting, uninterrupted, unnodding, unrelaxing, unrelenting, unremitting, unshifting, unsleeping, unswerving, untiring, unvaried, unvarying, unwavering, unwearied, unwearying, unwinking, unyielding, utterly attentive, vital, vivid, weariless, well-built, well-constructed, well-founded, well-grounded, well-made