in·​de·​fat·​i·​ga·​ble | \ˌin-di-ˈfa-ti-gə-bəl \

Definition of indefatigable 

: incapable of being fatigued : untiring an indefatigable worker

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Other Words from indefatigable

indefatigability \ˌin-​di-​ˌfa-​ti-​gə-​ˈbi-​lə-​tē \ noun
indefatigableness \ˌin-​di-​ˈfa-​ti-​gə-​bəl-​nəs \ noun
indefatigably \ˌin-​di-​ˈfa-​ti-​gə-​blē \ adverb

Examples of indefatigable in a Sentence

a person of indefatigable patience an indefatigable laborer who can work from sunrise to sunset

Recent Examples on the Web

The indefatigable Stephen Daldry directs this, too, and the ensemble of chattering, witty, thoughtful, campy friends (snaps to Michael Walters and Hubert Burton, reappearing as a conceptual artist) is faultless. Hamish Bowles, Vogue, "What’s on at the Theater? A Comprehensive Guide to London’s Best Shows This Fall," 18 Oct. 2018 Nunes, the chair of the House Intelligence Committee, has been the Trump administration’s most effective and indefatigable supporter on this issue. Dylan Matthews, Vox, "Paul Ryan is helping Trump undermine the rule of law," 27 July 2018 But the resilient and indefatigable Croats won’t be an easy out. Brian Straus,, "France vs. Croatia: A First Look at Their World Cup Final Matchup," 11 July 2018 Sadly, Till’s mother, the indefatigable Mamie Till Mobley, is no longer alive to experience this justice delayed. Ellen Mcgirt, Fortune, "raceAhead: Fresh Justice for Emmett Till?," 12 July 2018 With indefatigable energy, many public company CEOs drive nearby ubiquitous campaigns to convey their message around the nation and around the world relying upon vivid imagery. Jeffrey Sonnenfeld, Fortune, "Why CEOs Make Great Politicians," 14 June 2018 While Holmes has kept quiet herself, the 34-year-old founder still has a champion in the indefatigable venture capitalist Tim Draper, who told Cheddar on Tuesday that the real fraud in the Theranos mess is the media. Maya Kosoff, The Hive, "Theranos’s Former President Has a Jaw-Dropping Explanation for Why He’s Innocent," 20 June 2018 Such was the messianic zeal and indefatigable effort of those FBI and IRS investigators, you’d be forgiven for thinking the U.S. invented the game rather than having largely ignored it for decades. David Hirshey, WSJ, "World Cup Books Reviewed: The World Without America," 7 June 2018 Among the breakout superstars of the 2018 Winter Olympics was 17-year-old snowboarder Chloe Kim, whose Valley Girl vibe almost belied her technical gold-medal finesse and, by all accounts, indefatigable work ethic. Mari Uyehara, GQ, "How Title IX Gave Rise to the Dad Fan," 11 June 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'indefatigable.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of indefatigable

1608, in the meaning defined above

History and Etymology for indefatigable

Middle French, from Latin indefatigabilis, from in- + defatigare to fatigue, from de- + fatigare to fatigue

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Dictionary Entries near indefatigable


in deep shit



in default


in defeat

Statistics for indefatigable

Last Updated

16 Nov 2018

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Time Traveler for indefatigable

The first known use of indefatigable was in 1608

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More Definitions for indefatigable



English Language Learners Definition of indefatigable

: able to work or continue for a very long time without becoming tired

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More from Merriam-Webster on indefatigable

Thesaurus: All synonyms and antonyms for indefatigable

Spanish Central: Translation of indefatigable

Nglish: Translation of indefatigable for Spanish Speakers

Comments on indefatigable

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a nest or breeding place

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