indefatigable

showing no signs of weariness even after long hard effort an indefatigable laborer who can work from sunrise to sunset Synonyms tireless, inexhaustible, unflagging, untiring, wearilessRelated Words assiduous, conscientious, diligent, meticulous, painstaking, sedulous; determined, dogged, patient, persevering, persistent, pertinacious, plodding, relentless, steadfast, steady, stubborn, tenacious, unabating, unfailing, unfaltering, unflinching, unrelenting, unremitting, unwavering; active, busy, dynamic, energetic, feverish, spirited, vigorous; hard, industrious, intense, laborious, slavish, strenuousNear Antonyms indolent, lackadaisical, laggard, lazy, listless, shiftless, slothful, sluggish; apathetic, casual, desultory, languid, spiritless; beat, broken, burned-out (or burnt-out), done in, drained, enervated, jaded, overtaxed, overworked, played out, sapped, spent, tuckered (out), wearied, worn-out