untiring
adjective uk/ʌnˈtaɪə.rɪŋ/ us/ʌnˈtaɪr.ɪŋ/
不知疲倦的；坚持不懈的；永不减弱的
If someone has untiring energy, interest, or enthusiasm, their energy, interest, or enthusiasm never becomes weaker.
We'd like to thank George for his untiring efforts on our behalf. 对于乔治为我们做出的不懈努力，我们表示感谢。
Synonyms: indefatigable tirelessunflagging