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Showing results for infallible.
Definitions

infallible

[in-fal-uh-buhl] / ɪnˈfæl ə bəl /
ADJECTIVE
unerring, dependable
Synonyms
STRONGEST
authoritative flawless foolproof unbeatable
WEAK
acceptable accurate agreeable apodictic certain correct effective effectual efficacious efficient exact faultless handy helpful impeccable incontrovertible inerrable inerrant omniscient perfect positive reliable satisfactory satisfying sure surefire true trustworthy undeceivable unfailing unimpeachable unquestionable useful
Antonyms
WEAK
erring fallible faulty imperfect

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.

They are never infallible or immune to misjudgment.

From Slate • Feb. 16, 2026

To be sure, the “lipstick index” was never infallible, or even very popular, as far as economic theories go.

From MarketWatch • Dec. 12, 2025

Why did a church with an infallible papal teacher need councils?

From The Wall Street Journal • Dec. 4, 2025

And never be afraid to change the sequence and tendencies of that infallible trio of pitches, using instinct and feel to amplify his physical talent.

From Los Angeles Times • Jul. 1, 2025

In the United States the FBI, which often has to extract DNA in criminal cases, considers the test, when done with the latest technology, infallible.

From "Endgame" by Frank Brady

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