Definition of indefatigable :
Incapable of being fatigued; not readily exhausted; unremitting in labor or effort; untiring; unwearying; not yielding to fatigue; as, indefatigable exertions, perseverance, application.
continuous (part of speech: adjective)
habitual, unvarying, continuing, perpetual, continuous, robot-like, level, monotonous, straight, nonstop, unending, cyclical, sequential, uniform, unremitting, everlasting, undeviating, consecutive, seamless, connected, homogeneous, incessant, undying, unceasing, repeated, invariable, perennial, recurrent, regular, continual, ceaseless, unbroken, even, interminable, endless, coherent, repetitive, featureless, un-intermittent, unchanging, flat, monolithic, gapless, consistent
resolute (part of speech: adjective)
headstrong, decided, implacable, unflinching, intent, courageous, staunch, steely, dedicated, bullheaded, tireless, willing, valiant, loyal, spunky, bold, ruthless, devoted, firm, reliable, resolute, relentless, zealous, dauntless, set, dogged, plucky, steady, faithful, insistent, iron-willed, strong-minded, resolved, inexorable, fearless, uncompromising, deliberate, serious, stern, unshakeable, earnest, constant, thorough, unyielding, committed, stubborn, true, unchangeable, decisive, diligent, tough, strong-willed, hearty, unbending, determined
tenacious (part of speech: adjective)
persevering (part of speech: adjective)
- In a short time the indefatigable Cimarrons had built a fine large hut of cane: one room for myself and the baggage, a large assembly- room for the people, and a special apartment for cooking. - "The Former Philippines thru Foreign Eyes", Tomás de Comyn Fedor Jagor Rudolf Ludwig Carl Virchow Charles Wilkes.
- Without the use of the tools or the machinery familiar to the European, each individual could have done little; but acting in large masses, and under a common direction, they were enabled by indefatigable perseverance to achieve results, to have attempted which might have filled even the European with dismay. - "History-of-the-Conquest-of-Peru-with-a-preliminary-view-of-the-civilization-of-the-Incas", Prescott, William Hickling.
- " I hear they's a new hasher at Bill Lainey's hotel," pursued the indefatigable Jimmie. - "The Heart of the Range", William Patterson White.