Synonyms of the word 
INDEFATIGABLE → ENERGETIC - TIRELESS - UNFLAGGING - UNWEARYING
indefatigable
- adj. Extremely persistent and untiring.
energetic
- adj. Possessing, exerting, or displaying energy.
- adj. Of or relating to energy.
tireless
- adj. Indefatigable, untiring and not yielding to fatigue.
- adj. Without a tire (wheel covering); tyreless.
unflagging
- adj. Never tiring or lacking energy; without rest; without slowing.
unwearying
- adj. Untiring; not becoming tired.
If you are interested in words, visit the following sites :
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