indefatigable /ˌɪndɪˈfætɪgəbəl/ adjective /ˌɪndɪˈfætɪgəbəl/
adjective
Learner's definition of INDEFATIGABLE
[more indefatigable; most indefatigable] formal
: able to work or continue for a very long time without becoming tired : tireless不知疲倦的 — indefatigably
/ˌɪndɪˈfætɪgəbli/ adverb