untiring

showing no signs of weariness even after long hard effort the camel's reputation as an untiring beast of burden the detective's untiring investigation of the crime finally led to several arrests Synonyms indefatigable, inexhaustible, unflagging, tireless, 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