From Longman Dictionary of Contemporary Englishindefatigablein‧de‧fat‧i‧ga‧ble /ˌɪndɪˈfætɪɡəbəl/ adjective formal ENERGETICdetermined and never giving up SYN tireless an indefatigable campaigner for human rights —indefatigably adverb
Examples from the Corpus
indefatigable• Meanwhile, the body is fluid, strong and apparently indefatigable.• Better-known candidates fell by the wayside, but Alexander kept going, like the indefatigable bunny in battery advertisements.• She won because of her indefatigable energy and willpower, mobilizing women in state after state where the Amendment was contested.• In New York, the indefatigable Olmsted refused to give up the battle.• Not surprisingly, the indefatigable Paul-Henri Spaak was in the forefront of these arguments for new departures.• But the indefatigable Swans, yellow labels flapping from their shoulder bags, would never dream of sitting anything out.• Virginia was an indefatigable walker, both in Sussex and London.• That kind of instinctive, indefatigable willingness to engage is a gift, Mr Caen, as unteachable as it is unbuyable.• an indefatigable workerOrigin indefatigable (1600-1700) Early French indéfatigable, from Latin indefatigabilis, from fatigare; → FATIGUE