Source : WordNet®

unflagging
     adj 1: showing sustained enthusiastic action with unflagging
            vitality; "an indefatigable advocate of equal rights";
            "a tireless worker"; "unflagging pursuit of
            excellence" [syn: {indefatigable}, {tireless}, {unwearying}]
     2: unceasing; "unfailing loyalty"; "unfailing good spirits";
        "unflagging courtesy" [syn: {unfailing}]