tireless

/ˈtaɪərləs/
adjective
  1. Having or showing great energy and effort; never stopping or becoming tired.
    • Her tireless dedication to teaching earned her a special award.
    • The scientist's tireless research led to a major medical breakthrough.
    • The tireless volunteers worked all night to help the flood victims.
Antonyms
What does "tireless" mean? | whatsthatwordmean | whatsthatwordmean