Definition of indefatigable adjective from the Oxford Advanced Learner's Dictionary



BrE BrE//ˌɪndɪˈfætɪɡəbl//
; NAmE NAmE//ˌɪndɪˈfætɪɡəbl//
(formal, approving)
jump to other results
never giving up or getting tired of doing something an indefatigable defender of human rights She was indefatigable in her search for the truth. Word Originearly 17th cent.: from French, or from Latin indefatigabilis, from in- ‘not’ + de- ‘away, completely’ + fatigare ‘wear out’.
See the Oxford Advanced American Dictionary entry: indefatigable