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 infallibility (audio) \ noun
infallibly \ (ˌ)in-​ˈfa-​lə-​blē How to pronounce infallibly (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 To put our politicians on pedestals or treat them as infallible is to set them — and us — up for failure and disappointment. Sara Li, Teen Vogue, "Don't Stan Presidential Candidates the Way You Stan BTS," 15 Jan. 2020 The eggplant suggestion comes from Molly Stevens, an infallible teacher and writer. Corby Kummer, The Atlantic, "The 5 Best Cookbooks of 2019," 11 Dec. 2019 Though obviously not infallible, such groups are unlikely to make mistakes on the level of, say, trusting classified information with someone likely to discuss it on television mere months later. Jordan Runtagh,, "The Storming of Area 51: A Covert Journey to the Heart of America’s Worst-Kept Secret," 13 Jan. 2020 Joe Biden claimed to be politically infallible in the face of attacks lobbed at him by rivals to the 2020 Democratic presidential nomination. Naomi Lim, Washington Examiner, "'Everybody who’s hit me is out': Biden touts durability against 2020 Democratic rival attacks," 17 Jan. 2020 Two cents Get to Fields: Fields is not completely infallible. Orion Sang, Detroit Free Press, "Michigan football vs. Ohio State: Scouting report, prediction," 28 Nov. 2019 Firmino, of course, played his part in the win, scoring with an audacious chip past Ederson who, up until that point, had appeared infallible in the City goal., "Roberto Firmino: 9 of His Best Premier League Goals After Becoming First Brazilian to Hit 50," 3 Sep. 2019 The judges at Cannes are no more infallible than the voters at the Academy Awards, but in this case the laurels were well deserved, and, amid the plaudits, there was a shade of relief. Anthony Lane, The New Yorker, "“Parasite” Explores What Lies Beneath," 11 Oct. 2019 Comcast customer service reps are also quick to blame customers and insist that Comcast's data meter is infallible, even when customers measure their own usage and find possible mistakes in the Comcast meter. Jon Brodkin, Ars Technica, "Comcast incorrectly charged 2,000 customers for exceeding data cap," 9 Oct. 2019

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

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

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Cite this Entry

“Infallible.” Dictionary, Merriam-Webster, Accessed 5 Jun. 2020.

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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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