Synonyms and related words :
abiding, accordant, active, age-long, aged, ageless, alike, ancient, antique, ardent, articulated, assiduous, atom, atomic mass, atomic number, atomic weight, automatic, balanced, beaten, catenated, ceaseless, changeless, chattering, chronic, clinging, close, coeternal, colorfast, committed, compliant, concatenated, confirmed, conforming, connected, conscientious, consistent, consonant, continual, continued, continuing, continuous, correspondent, cyclical, dateless, dedicated, deep-dyed, delicate, dependable, determined, devoted, devout, diligent, direct, diuturnal, dogged, double-dyed, durable, duteous, dutiful, dyed-in-the-wool, endless, enduring, equable, equal, eternal, eterne, even, ever-being, ever-durable, ever-during, evergreen, everlasting, everliving, exact, express, fadeless, faithful, fast, featureless, fine, firm, fixed, flat, flinty, frequent, frozen, gapless, habitual, hackneyed, hardy, homogeneous, immediate, immemorial, immobile, immovable, immutable, inalterable, incessant, incommutable, inconvertible, indefatigable, indefeasible, indelible, indestructible, indomitable, industrious, inerrable, inerrant, inert, infallible, infinite, inflexible, ingrain, ingrained, insistent, insusceptible of change, intact, interminable, intransient, intransmutable, invariable, inveterate, invincible, inviolate, irretrievable, irreversible, irrevocable, joined, jointless, lasting, level, liege, linked, long-lasting, long-lived, long-standing, long-term, longeval, longevous, loyal, machine gun, macrobiotic, marble-constant, mathematical, measured, mechanical, methodic, methodical, meticulous, micrometrically precise, microscopic, mindful, monolithic, monotonous, never-ceasing, never-ending, never-tiring, nice, noble, nonreturnable, nonreversible, nonstop, nonterminating, nonterminous, observant, obstinate, of a piece, of long duration, of long standing, olamic, ordered, orderly, oscillating, patient, patient as Job, perdurable, perduring, perennial, periodic, permanent, perpetual, perseverant, persevering, persistent, persisting, pertinacious, pinpoint, plodding, plugging, practicing, precise, preoccupied, pulsating, punctilious, punctual, quantum, quiescent, rapid, rapt, recurrent, recurring, refined, regardful, regular, regular as clockwork, relentless, religious, religiously exact, remaining, repeated, repetitive, resolute, reverseless, rigid, rigorous, robotlike, round-the-clock, routine, running, scientific, scientifically exact, scrupulous, seamless, sedulous, sempervirent, sempiternal, serried, set, settled, severe, single-minded, sleepless, slogging, smooth, solid, sot, square, stabile, stable, staccato, static, stationary, staunch, staying, steadfast, steady, steely, stereotyped, straight, strict, stubborn, stuttering, subtle, sustained, systematic, tenacious, tested, timeless, tireless, torpid, tough, tried, tried and true, trite, TRUE, true-blue, trusty, twenty-four-hour, unabating, unalterable, unalterative, unaltered, unbending, unbroken, unceasing, unchangeable, unchanged, unchanging, unchecked, unconquerable, undaunted, undeflectable, undestroyed, undeviating, undifferentiated, undiscouraged, undiversified, undrooping, unending, unerring, unfading, unfailing, unfaltering, unflagging, unflappable, unflinching, uniform, unintermitted, unintermittent, unintermitting, uninterrupted, unmodifiable, unmovable, unnodding, unrelaxing, unrelenting, unrelieved, unremitting, unrestorable, unreturnable, unruffled, unshakable, unshakeable, unshaken, unshifting, unsleeping, unstopped, unsusceptible, unswerving, untiring, unvariable, unvaried, unvarying, unwavering, unwearied, unwearying, unwinking, unyielding, utterly attentive, valence, vibrating, vital, weariless, well-trodden, well-worn, without end,