never giving up or getting tired of doing something 不屈不挠的;不知疲倦的 an indefatigable defender of human rights 不屈不挠的人权捍卫者 She was indefatigable in her search for the truth. 她孜孜不倦地寻找真理。
Word Originearly 17th cent.: from French, or from Latin indefatigabilis, from in- ‘not’ + de- ‘away, completely’ + fatigare ‘wear out’.