THESAURUS
untiring
assiduous, cartilaginous, chewy, cohesive, constant, continuing, coriaceous, dedicated, determined, diligent, dogged, durable, enduring, faithful, fibrous, gristly, hard, hardy, immutable, inalterable, indefatigable, indomitable, industrious, inexhaustible, insistent, invincible, lasting, leatherlike, leathery, loyal, never-tiring, obstinate, patient, patient as Job, permanent, perseverant, persevering, persistent, persisting, pertinacious, plodding, plugging, preoccupied, rapt, relentless, resistant, resolute, ropy, sedulous, sinewy, single-minded, sleepless, slogging, stable, steadfast, steady, stiff, stringy, strong, stubborn, tenacious, tireless, tough, tough as leather, unabating, unconquerable, undaunted, undiscouraged, undrooping, unfailing, unfaltering, unflagging, unflinching, unintermitting, uninterrupted, unnodding, unrelaxing, unrelenting, unremitting, unsleeping, unswerving, unwavering, unwearied, unwearying, unwinking, utterly attentive, vigorous, viscid, weariless, wiry
ROGET THESAURUS
untiring
Perseverance
N
perseverance, continuance, permanence, firmness, constancy, steadiness, singleness of purpose, tenacity of purpose, persistence, plodding, patience, sedulity, pertinacy, pertinacity, pertinaciousness, iteration, bottom, game, pluck, stamina, backbone, grit, indefatigability, indefatigableness, bulldog courage, persevering, constant, steady, steadfast, undeviating, unwavering, unfaltering, unswerving, unflinching, unsleeping, unflagging, undrooping, steady as time, unrelenting, unintermitting, unremitting, plodding, industrious, strenuous, pertinacious, persisting, persistent, solid, sturdy, staunch, stanch, true to oneself, unchangeable, unconquerable, indomitable, game to the last, indefatigable,
untiring, unwearied, never tiring, through evil report and good report, through thick and thin, through fire and water, per fas et nefas, without fail, sink or swim, at any price, vogue la galere, never say die, give it the old college try, vestigia nulla retrorsum, aut vincer aut mori, la garde meurt et ne se rend pas, tout vient a temps pour qui sait attendre.