in·​fal·​li·​ble | \ (ˌ)in-ˈfa-lə-bəl How to pronounce infallible (audio) \

Definition of infallible

1 : incapable of error : unerring an infallible memory
2 : not liable to mislead, deceive, or disappoint : certain an infallible remedy
3 : incapable of error in defining doctrines touching faith or morals

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Other Words from infallible

infallibility \ (ˌ)in-​ˌfa-​lə-​ˈbi-​lə-​tē How to pronounce infallible (audio) \ noun
infallibly \ (ˌ)in-​ˈfa-​lə-​blē How to pronounce infallible (audio) \ adverb

Synonyms & Antonyms for infallible



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Did You Know?

Watch out when you hear about infallible predictions, an infallible plan, an infallible cure, or even infallible lip gloss. Infallible isn't a claim that scientists, engineers, and doctors like to make, so you're probably getting better information when the word not comes first. You may have heard the phrase "papal infallibility", which refers to the official position of the Roman Catholic church, adopted in the 19th century, that certain solemn statements made by a Pope about faith or morals were not to be questioned. Popes since then have been careful not to make many of these statements.

Examples of infallible in a Sentence

I never claimed to be infallible. There is no infallible remedy to these problems.
Recent Examples on the Web There is no one on the face of the Earth that has a memory that’s infallible. Monivette Cordeiro,, "Mom questions dropped charges in 1-year-old’s hot-car death in Orlando: ‘All I’m asking for is justice’," 31 Dec. 2020 Parents also should know that the new technologies being used to evaluate students aren’t infallible. Lisa Ward, WSJ, "Data Privacy in the Age of Online Learning," 8 Dec. 2020 Although projections vary from one model to another and researchers warn that no forecast is infallible, the models agree on one thing: that Connecticut will add significantly to its current total of 5,146 deaths linked to COVID-19. Alex Putterman,, "As pandemic intensifies, statistical models project thousands more COVID-19 deaths in Connecticut," 7 Dec. 2020 That said, West was not infallible, and the draft is a Jackson Pollock paint job. Sporting Green Staff,, "Warriors draft roundtable: Keep or trade No. 2 pick? Confidence in Bob Myers?," 14 Nov. 2020 The Israelis are not infallible, but their security for 33 years now has depended on making careful power judgments. WSJ, "A George Melloan Sampler: A Global View Across the Decades," 1 Oct. 2020 The core belief in Orthodox Judaism is that the Torah — the Five Books of Moses, its additional 613 commandments, or mitzvot, and several volumes of subsequent scholarly commentary — represent the infallible word of God. Jonathan M. Pitts,, "Baltimore-area Orthodox rabbis work around electronics ban in planning for Yom Kippur in the coronavirus era," 25 Sep. 2020 Major corporations, research labs, and the medical community as a whole are not infallible in their work. Michael Brendan Dougherty, National Review, "There Is No Trump Vaccine," 16 Sep. 2020 But because no test is infallible, some cases will be missed and some people will be forced to miss work due to false positives. Ken Alltucker, USA TODAY, "Inaccurate results from rapid COVID tests raise concerns about widespread screening," 25 Aug. 2020

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'infallible.' 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 infallible

15th century, in the meaning defined at sense 1

History and Etymology for infallible

Middle English, from Medieval Latin infallibilis, from Latin in- + Late Latin fallibilis fallible

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Time Traveler for infallible

Time Traveler

The first known use of infallible was in the 15th century

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Statistics for infallible

Last Updated

11 Jan 2021

Cite this Entry

“Infallible.” Dictionary, Merriam-Webster, Accessed 21 Jan. 2021.

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More Definitions for infallible


How to pronounce infallible (audio)

English Language Learners Definition of infallible

: not capable of being wrong or making mistakes : not fallible
: certain to work properly or succeed


in·​fal·​li·​ble | \ in-ˈfa-lə-bəl How to pronounce infallible (audio) \

Kids Definition of infallible

1 : not capable of being wrong an infallible memory
2 : certain to succeed : sure an infallible remedy

Other Words from infallible

infallibly \ -​blē \ adverb

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