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.

That is not to say humanity is infallible.

From Slate • May 28, 2026

For a while after that, they seemed totally infallible, a giant blue behemoth blocking out the light.

From BBC • May 6, 2026

But it does make clear that AI isn’t magic, nor are those who are making and marketing it infallible.

From Los Angeles Times • Mar. 26, 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

Even the trees were not as infallible a guide as they might have hoped, for there were wooded islands in the lake, and wide areas ashore where no trees grew.

From "A Dance with Dragons" by George R. R. Martin

Vocabulary lists containing infallible

The Vocabulary.com Top 1000

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"The Odyssey" by Homer, Books 1–7

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