un·tir·ing
adjective/ʌnˈtaɪərɪŋ/
/ʌnˈtaɪərɪŋ/
(approving)- continuing to do something for a long period of time with a lot of effort and/or enthusiasm
不知疲劳的；孜孜不倦的；坚持不懈的 - an untiring campaigner for human rights
孜孜不倦的人权活动家
Oxford Collocations DictionaryUntiring is used with these nouns:- perseverance
- an untiring campaigner for human rights