'Indefatigable' definitions:

Definition of 'indefatigable'

From: WordNet
adjective
Showing sustained enthusiastic action with unflagging vitality; "an indefatigable advocate of equal rights"; "a tireless worker"; "unflagging pursuit of excellence" [syn: indefatigable, tireless, unflagging, unwearying]

Definition of 'Indefatigable'

From: GCIDE
  • Indefatigable \In`de*fat"i*ga*ble\ ([i^]n`d[-e]*f[a^]t"[i^]*g[.a]*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. [1913 Webster]
  • Upborne with indefatigable wings. --Milton.
  • Syn: Unwearied; untiring; persevering; persistent. [1913 Webster]