In′de‐fat″i‐ga‐ble (ĭn′dē̍‐făt″ĭ‐gȧ‐b'l), a. [L. indefatigabilis: cf. OF. indefatigable. See In- not, and Defatigable, and cf. Infatigable.] 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.