indefatigable

adjective

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

: incapable of being fatigued : untiring

an indefatigable worker

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

Synonyms

• inexhaustible
• tireless
• unflagging
• untiring
• weariless

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

Jethro Tull – Bursting Out (1978) Led by the indefatigable Ian Anderson, Jethro may well be the one prog band best experienced live. —Ernesto Lechner, SPIN, 11 Apr. 2024

Dana Champion Los Angeles :: LSU coach Kim Mulkey is an indefatigable attention craver, who mistakenly believes the free press should serve as her public relations firm. —Los Angeles Times, 6 Apr. 2024

The seemingly indefatigable Princess Anne — the king’s younger sister — soldiers on. —Karla Adam, Washington Post, 24 Mar. 2024

Grunge rock’s most indefatigable missionaries, Melvins, will return this spring with Tarantula Heart, their umpteenth release since the turn of the millennium (or is that umphundredth?). —Kory Grow, Rolling Stone, 20 Mar. 2024

Perriello, a former member of Congress, was creative and indefatigable in his role as special envoy to the Democratic Republic of the Congo during President Barack Obama’s tenure, and his strong relationships on Capitol Hill will be critical for securing high-level attention from Washington. —John Prendergast, Foreign Affairs, 27 Feb. 2024

The indefatigable Harvey Mansfield recently urged Harvard colleagues and other academics to take steps toward recovering the true meaning of the Ivory Tower. —Paul O. Carrese, National Review, 13 Feb. 2024

In January, Bowman was condemned for praising Norman Finkelstein, the author and indefatigable Israel critic who compared the Hamas attacks to John Brown’s raid on Harpers Ferry, at a panel in Westchester. —Ross Barkan, New York Times, 7 Feb. 2024

The inflection point came with his indefatigable reporting on the 1996 murder of Tupac Shakur. —Michael Hiltzik, Los Angeles Times, 6 Feb. 2024

Word History

Etymology

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

First Known Use

1608, in the meaning defined above

Kids Definition

indefatigable

adjective

in·​de·​fat·​i·​ga·​ble ˌin-di-ˈfat-i-gə-bəl 

: capable of working a long time without tiring : tireless

an indefatigable teacher

indefatigably

-blē 

adverb