Synonyms to never-failing

abiding, age-long, aged, ancient, antique, changeless, chronic, commorant, constant, continuing, continuous, diuturnal, durable, dwelling, enduring, evergreen, firm, fixed, frozen, hardy, immobile, immutable, in residence, indefatigable, intact, intransient, inveterate, inviolate, lasting, living, living in, lodging, long-lasting, long-lived, long-standing, long-term, longeval, longevous, macrobiotic, of long duration, of long standing, perdurable, perduring, perennial, permanent, perpetual, persistent, persisting, quiescent, remaining, resident, residentiary, residing, rigid, sempervirent, solid, stable, static, stationary, staying, steadfast, steady, sticking, sustained, torpid, tough, unaltered, unceasing, unchangeable, unchanged, unchanging, unchecked, undestroyed, undying, unfading, unfailing, unfaltering, unqualified, unquestioning, unremitting, unshifting, unvaried, unvarying, vital, wholehearted, endure, abide, abide with, advance, afford, allow for, be exposed to, be proof against, be spared, be subjected to, be tough, bear, bear up, bear up against, bear with, bide, blink at, b