infallible

[ in-fal-uh-buhl ]

See synonyms for: infallible infallibility infallibly on Thesaurus.com

adjective

absolutely trustworthy or sure: an infallible rule.
unfailing in effectiveness or operation; certain: an infallible remedy.

not fallible; exempt from liability to error, as persons, their judgment, or pronouncements: an infallible principle.
Roman Catholic Church. immune from fallacy or liability to error in expounding matters of faith or morals by virtue of the promise made by Christ to the Church.

noun

an infallible person or thing.

Origin of infallible

First recorded in 1375–1425; late Middle English word from Medieval Latin word infallibilis.See in-³, fallible

synonym study For infallible

1, 2. See reliable.

Other words from infallible

in·fal·li·bil·i·ty, in·fal·li·ble·ness, noun
in·fal·li·bly, adverb
non·in·fal·li·ble, adjective
non·in·fal·li·bly, adverb

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use infallible in a sentence

They even threw shade at Taylor Swift and remained infallibly charming in the process.
Golden Globes Hosts Tina Fey & Amy Poehler’s Funniest Moments (Video) | Kevin Fallon | January 12, 2014 | THE DAILY BEAST
The reader wishes to infallibly remember that the date of the beheading of Charles I. was 1649.
Assimilative Memory | Marcus Dwight Larrowe (AKA Prof. A. Loisette)
I told you what would infallibly happen, and you know enough of the nature of the beast not to be surprized at it.
Private Letters of Edward Gibbon (1753-1794) Volume 1 (of 2) | Edward Gibbon
For some day, he said, Nicky will bring out a volume of his poems, and in that day he will infallibly turn to me.
The Creators | May Sinclair
In short, it would infallibly perish if abandoned before the age of three years.
Buffon's Natural History. Volume IX (of 10) | Georges Louis Leclerc de Buffon

The continuance of hostility, with the determined refusal of security for these privileges, will infallibly bring on separation.
The Loyalists of America and Their Times, Vol. 1 of 2 | Egerton Ryerson

British Dictionary definitions for infallible

infallible

/ (ɪnˈfæləbəl) /

adjective

not fallible; not liable to error
not liable to failure; certain; sure: an infallible cure

completely dependable or trustworthy

noun

a person or thing that is incapable of error or failure

Derived forms of infallible

infallibility or infallibleness, noun
infallibly, adverb

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

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