tireless
ti·re·less
adjective
1.
showing sustained enthusiastic action with unflagging vitality
- “an indefatigable advocate of equal rights”
- “a tireless worker”
- “unflagging pursuit of excellence”
2.
characterized by hard work and perseverance
Origin
From tire (“to become sleepy or weary”) + -less.
Related words
Word family
WordNet 2.1 (Princeton University). Wiktionary (CC BY-SA). CMU Pronouncing Dictionary. WordNet 2.1 Copyright Princeton University. All rights reserved. Wiktionary content is available under the Creative Commons Attribution-ShareAlike Licence.