Indefatigable
(a.) Incapable of being fatigued; not readily exhausted; unremitting in labor or effort; untiring; unwearying; not yielding to fatigue; as, indefatigable exertions, perseverance, application.
Similar Words:
Indefatigability Indefatigable Indefatigableness Indefatigably Indefatigation Indefeasibility Indefeasible Indefectibility Indefectible Indefective