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Synonyms

indefatigable

American  
[in-di-fat-i-guh-buhl] / ˌɪn dɪˈfæt ɪ gə bəl /

adjective

  1. incapable of being tired out; not yielding to fatigue; untiring.

    Synonyms:
    persevering , inexhaustible , tireless

indefatigable British  
/ ˌɪndɪˈfætɪɡəbəl /

adjective

  1. unable to be tired out; unflagging

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Word Forms

  • indefatigability noun
  • indefatigableness noun
  • indefatigably adverb

Etymology

Origin of indefatigable

1580–90; < Latin indēfatīgābilis untiring, equivalent to in- in- 3 + dēfatīgā ( re ) to tire out ( de-, fatigue ) + -bilis -ble

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

It’s a rollicking animal story; it’s also a tale of indefatigable love.

From The Wall Street Journal

Underlings have long marveled at his indefatigable work ethic.

From Los Angeles Times

Xenarios, who died of cancer on Sept. 6 at home in New York at age 79, was the indefatigable soul of the organization, leading it for 40 years until her retirement in 2017.

From The Wall Street Journal

But she is also indefatigable: She believes that she must win to save democracy, yet she seems to shoulder that formidable burden without breaking a sweat.

From Los Angeles Times

Tony Doherty, chair of the Bloody Sunday Trust, said: "This day is a tribute to the strength of the families, whose indefatigable campaign for justice has made this happen."

From BBC