Easily tired or wearied; capable of being fatigued.
Extremely persistent and untiring.
Capable of being wearied or tired out.
Incapable of being fatigued; not readily exhausted; unremitting in labor or effort; untiring; unwearying; not yielding to fatigue; as, indefatigable exertions, perseverance, application.
‘Upborne with indefatigable wings.’;
showing sustained enthusiastic action with unflagging vitality;
‘an indefatigable advocate of equal rights’; ‘a tireless worker’; ‘unflagging pursuit of excellence’;