Word Study
indefatigable
CIDE DICTIONARY
indefatigable, a. [L. indefatigabilis: cf. OF. indefatigable. See In- not, and Defatigable, and cf. Infatigable.].
Incapable of being fatigued; not readily exhausted; unremitting in labor or effort; untiring; unwearying; not yielding to fatigue; as, indefatigable exertions, perseverance, application. South. [1913 Webster]
"Upborne with indefatigable wings."
Syn. -- Unwearied; untiring; persevering; persistent.
OXFORD DICTIONARY
indefatigable, adj. (of a person, quality, etc.) that cannot be tired out; unwearying, unremitting.
Derivative
indefatigability n. indefatigably adv.
Etymology
obs. F ind{eacute}fatigable or L indefatigabilis (as IN-(1), defatigare wear out)
THESAURUS
indefatigable
abiding, ardent, assiduous, constant, continuing, continuous, determined, diligent, dogged, enduring, energetic, faithful, fervent, hard, hardworking, immutable, inalterable, indomitable, industrious, inexhaustible, insistent, invincible, laborious, lasting, loyal, never idle, never-tiring, obstinate, painstaking, patient, patient as Job, permanent, perseverant, persevering, persistent, persisting, pertinacious, plodding, plugging, preoccupied, rapt, relentless, remaining, resolute, sedulous, single-minded, sleepless, slogging, stable, staying, steadfast, steady, sticking, strenuous, stubborn, sustained, tenacious, tireless, unabating, unceasing, unconquerable, undaunted, undiscouraged, undrooping, undying, unfailing, unfaltering, unflagging, unflinching, unintermitting, uninterrupted, unnodding, unrelaxing, unrelenting, unremitting, unsleeping, unsparing, unswerving, untiring, unwavering, unwearied, unwearying, unwinking, utterly attentive, vehement, vigorous, weariless, zealousROGET THESAURUS
indefatigable
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.Activity
N activity, briskness, liveliness, animation, life, vivacity, spirit, dash, energy, snap, vim, nimbleness, agility, smartness, quickness, velocity, alacrity, promptitude, despatch, dispatch, expedition, haste, punctuality, eagerness, zeal, ardor, perfervidum aingenium, empressement, earnestness, intentness, abandon, vigor, devotion, exertion, industry, assiduity, assiduousness, sedulity, laboriousness, drudgery, painstaking, diligence, perseverance, indefatigation, habits of business, vigilance, wakefulness, sleeplessness, restlessness, insomnia, pervigilium, insomnium, racketing, movement, bustle, stir, fuss, ado, bother, pottering, fidget, fidgetiness, flurry, officiousness, dabbling, meddling, interference, interposition, intermeddling, tampering with, intrigue, press of business, no sinecure, plenty to do, many irons in the fire, great doings, busy hum of men, battle of life, thick of the action, housewife, busy bee, new brooms, sharp fellow, sharp blade, devotee, enthusiast, zealot, meddler, intermeddler, intriguer, busybody, pickthank, hummer, hustler, live man, rustler, active, brisk, brisk as a lark, brisk as a bee, lively, animated, vivacious, alive, alive and kicking, frisky, spirited, stirring, nimble, nimble as a squirrel, agile, light-footed, nimble-footed, featly, tripping, quick, prompt, yare, instant, ready, alert, spry, sharp, smart, fast, quick as a lamplighter, expeditious, awake, broad awake, go-ahead, live wide-awake, forward, eager, strenuous, zealous, enterprising, in earnest, resolute, industrious, assiduous, diligent, sedulous, notable, painstaking, intent, indefatigable, unwearied, unsleeping, never tired, plodding, hard-working, businesslike, workaday, bustling, restless, restless as a hyena, fussy, fidgety, pottering, busy, busy as hen with one chicken, working, at work, on duty, in harness, up in arms, on one's legs, at call, up and doing, up and stirring, busy, occupied, hard at work, hard at it, up to one's ears in, full of business, busy as a bee, busy as a one-armed paperhanger, meddling, meddlesome, pushing, officious, overofficious, intrigant, astir, stirring, agoing, afoot, on foot, in full swing, eventful, on the alert, actively, with life and spirit, with might and main &c, with haste, with wings, full tilt, in mediis rebus, Int, be alive, look alive, look sharp!, move on, push on!, keep moving!, go ahead!, stir your stumps!, age quod agis!, jaldi!, karo!, step lively!, carpe diem, seize the day, nulla dies sine linea, nec mora nec requies, the plot thickens, No sooner said than done, veni vidi vici, catch a weasel asleep, abends wird der Faule fleissig, dictum ac factum, schwere Arbeit in der Jugend ist sanfte Ruhe im Al, hard work in youth means soft rest in age, the busy hum of men.For further exploring for "indefatigable" in Webster Dictionary Online