C2 adjective /ˌɪndɪˈfætɪɡəbl̩/
indefatigable
不知疲倦
Meaning
persisting tirelessly; incapable of being fatigued
Example
Her indefatigable spirit kept the team motivated during the long project.
她那不知疲倦的精神在漫长的项目中激励着团队。