indefatigable
Impossible to tire
Indefatigable means tireless, incapable of being worn out.
Someone indefatigable persists without flagging: an indefatigable advocate for civil rights, her indefatigable optimism.
The word carries admiration—it suggests not just endurance but inexhaustible energy in pursuit of a goal.
Continuing without pause
- tenaciousStubbornly determined to continue
- doggedStubbornly persevering
- unwaveringSteady and unchanging
- unflaggingPersistently energetic
steadfast · resolute · unyielding · unrelenting · unswerving · unfaltering · inexorable · unshakeable
Never losing energy
- vigorousHaving great physical energy
- dynamicActive and changing
- spiritedFull of vim
- livelyAnimated and energetic
vivacious · animated · exuberant · enthusiastic · zealous · vibrant · buoyant · sprightly
Capacity for sustained effort
- resilienceCapacity to recover quickly
- fortitudeEnduring courage under pain
- perseveranceSustained resolve despite obstacles
- gritDetermination or abrasive particles
determination · toughness · hardiness · staying power · durability · robustness · vigor · patience
relentless
Continuing without pause
- tenaciousStubbornly determined to continue
- doggedStubbornly persevering
- unwaveringSteady and unchanging
unflagging · steadfast · resolute · unyielding · unrelenting · unswerving · unfaltering · inexorable · unshakeable · implacable
tireless
Never losing energy
lively · vivacious · animated · exuberant · enthusiastic · zealous · vibrant · buoyant · sprightly · ebullient
stamina
Capacity for sustained effort
- resilienceCapacity to recover quickly
- fortitudeEnduring courage under pain
- perseveranceSustained resolve despite obstacles
grit · determination · toughness · hardiness · staying power · durability · robustness · vigor · patience · longevity