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Showing results for indefatigable. Search instead for indefatiga.
Definitions

indefatigable

[in-di-fat-i-guh-buhl] / ˌɪn dɪˈfæt ɪ gə bəl /
ADJECTIVE
untiring
Synonyms
STRONGEST
assiduous diligent dogged energetic inexhaustible painstaking relentless tireless unflagging unwavering vigorous
WEAK
active bound and determined dead set on determined hell-bent industrious ironclad nose to grindstone patient persevering persistent pertinacious sedulous steadfast stop-at-nothing strenuous unfaltering unflinching unremitting unwearied unwearying
Antonyms
STRONGEST
changing idle inactive indifferent lazy lethargic negligent tired wavering
WEAK
fatigued weary

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.

But an indefatigable Volkanovski's agility and relentless striking eventually wore down his flagging challenger, who was unable to land a knockout in the final round.

From Barron's • Feb. 1, 2026

Mr. Dooley is also a discerning and indefatigable researcher.

From The Wall Street Journal • Jan. 21, 2026

Underlings have long marveled at his indefatigable work ethic.

From Los Angeles Times • Oct. 30, 2025

It also said he was "indefatigable to the end" and "driven by relentless curiosity and a deep attention to the present and to people".

From BBC • Sep. 4, 2025

A more resolute, indefatigable pioneer never wrought amidst rocks and dangers.

From "Jane Eyre" by Charlotte Brontë

From Roget's 21st Century Thesaurus, Third Edition Copyright © 2013 by the Philip Lief Group.