infallible

American  

[in-fal-uh-buhl] / ɪnˈfæl ə bəl /

adjective

1. absolutely trustworthy or sure.

   an infallible rule.

2. unfailing in effectiveness or operation; certain.

   an infallible remedy.

3. not fallible; exempt from liability to error, as persons, their judgment, or pronouncements.

   an infallible principle.

4. 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.

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noun

1. an infallible person or thing.

infallible British  

/ ɪnˈfæləbəl /

adjective

1. not fallible; not liable to error

2. not liable to failure; certain; sure

   an infallible cure

3. completely dependable or trustworthy

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noun

1. a person or thing that is incapable of error or failure

Related Words

See reliable.

Other Word Forms

• infallibility noun
• infallibleness noun
• infallibly adverb
• noninfallible adjective
• noninfallibly adverb

Etymology

Origin of infallible

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

Related Words

• authoritative
• flawless
• foolproof
• unbeatable