Definitions

from The American Heritage® Dictionary of the English Language, 5th Edition.

  • adjective Having or showing a capacity for persistent effort; not tiring or relenting: synonym: tireless.

from The Century Dictionary.

  • Not defatigable; incapable of being fatigued; not easily exhausted; not yielding to fatigue; unremitting in labor or effort.
  • Synonyms Unwearied, untiring, tireless, unflagging, persevering, assiduous, persistent, sedulous.

from the GNU version of the Collaborative International Dictionary of English.

  • adjective Incapable of being fatigued; not readily exhausted; unremitting in labor or effort; untiring; unwearying; not yielding to fatigue.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • adjective Extremely persistent and untiring.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • adjective showing sustained enthusiastic action with unflagging vitality

Etymologies

from The American Heritage® Dictionary of the English Language, 4th Edition

[Obsolete French indéfatigable, from Latin indēfatīgābilis : in-, not; see in– + dēfatīgāre, to tire out (dē-, intensive pref.; see de– + fatīgāre, to weary).]

from Wiktionary, Creative Commons Attribution/Share-Alike License

From Latin indēfatīgābilis ("untiring"), from in- ("not") + de- ("away") + fatīgō ("I tire").

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Examples

  • Armstrong had long been known as an indefatigable spear-carrier for Harry Chandler, but at this moment he seemed unaware that the wind had shifted at Times headquarters.

    Colossus Michael Hiltzik 2010

  • Armstrong had long been known as an indefatigable spear-carrier for Harry Chandler, but at this moment he seemed unaware that the wind had shifted at Times headquarters.

    Colossus Michael Hiltzik 2010

  • I thought that, according to George Galloway, only certain Middle Eastern dictators could be termed indefatigable?

    Atlantic Review 2009

  • Larsen: If you're ADD and you still have a kind of indefatigable creative drive ...

    Printing: Interview with Stephen Larsen, author, THE FUNDAMENTALIST MIND 2008

  • Larsen: If you're ADD and you still have a kind of indefatigable creative drive ...

    Interview with Stephen Larsen, author, THE FUNDAMENTALIST MIND 2008

  • Could he ever overshadow the 'indefatigable' moment with Saddam Hussein?

    Keep On Rockin' In The Trots World Johnny Guitar 2006

  • Officers generally understand by the words "indefatigable," and

    The Authoritative Life of General William Booth 1881

  • In his first words to the press on Tuesday from the Florencia airport in Colombia, Moncayo thanked the "indefatigable" Senator Cordoba, Colombians for Peace, the Catholic Church, and the International Red Cross.

    New on venezuelanalysis.com james 2010

  • WASHINGTON, Aug 26 (OneWorld. net) - Eighty-nine years after U.S. women finally won the right to vote, advocacy groups are pressing the Obama administration to promote women's equality worldwide and paying tribute to an "indefatigable" champion of women's rights, Senator Edward M. Kennedy.

    OneWorld.net (U.S.) - beyond your own borders 2010

  • WASHINGTON, Aug 26 (OneWorld. net) - Eighty-nine years after U.S. women finally won the right to vote, advocacy groups are pressing the Obama administration to promote women's equality worldwide and paying tribute to an "indefatigable" champion of women's rights, Senator Edward M. Kennedy.

    OneWorld.net (U.S.) - beyond your own borders 2010

Comments

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  • When I'm three sheets to the wind, I tend to invert the g and t, with hilarious results.

    October 23, 2007

  • I do the inverting the g and t thing, too. It is rather comical, but sometimes very embarrassing.

    January 18, 2008

  • I first heard this word in the book "Brave New World". I swear it was used like, every ten pages.

    February 21, 2009

  • His life was one of indefatigable labor.

    August 31, 2010

  • But Mr. Lauren, the indefatigable fashion icon, re-upped through March 2013

    January 6, 2011

  • I had this word yesterday on my Word Of The Day app on my Nook Color.

    June 9, 2012