Indefatigable
Pronunciation : In`de*fat"i*ga*ble
Part of Speech : a.
Etymology : [L. indefatigabilis: cf. OF. indefatigable. See In- not, and Defatigable, and cf. Infatigable.]
Definition : Defn: Incapable of being fatigued; not readily exhausted; unremitting in labor or effort; untiring; unwearying; not yielding to fatigue; as, indefatigable exertions, perseverance, application. "A constant, indefatigable attendance." South. Upborne with indefatigable wings. Milton.
Syn. -- Unwearied; untiring; persevering; persistent.
Source : Webster's Unabridged Dictionary, 1913