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.

A lapse in judgment has sent the previously infallible industry visionary, with Agnes in tow, into self-imposed, self-described exile on Maui, where the Hopkinses have built a showstopper of a house.

From The Wall Street Journal • Apr. 17, 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

They are never infallible or immune to misjudgment.

From Slate • Feb. 16, 2026

They aren't infallible but they will increase the hassle factor for criminals.

From BBC • Feb. 7, 2026

Notwithstanding that the devil, played by Cook, gives himself away at once by wearing red socks, the infallible mark of a cad, Dudley falls into conversation with him.

From "Words Like Loaded Pistols" by Sam Leith

Vocabulary lists containing infallible

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"The Odyssey" by Homer, Books 1–7

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