approval If you describe someone or their efforts as tireless, you approve of the fact that they put a lot of hard work into something, and refuse to give up or take a rest. Mother Teresa's tireless efforts to help the poor. + tirelessly tire·less·ly He worked tirelessly for the cause of health and safety. working very hard in a determined way without stopping
showing sustained enthusiastic action with unflagging vitality; "an indefatigable advocate of equal rights"; "a tireless worker"; "unflagging pursuit of excellence"