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.

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

From BBC • May 6, 2026

They are never infallible or immune to misjudgment.

From Slate • Feb. 16, 2026

For the cubicle set, he was Kafka with an American accent and an infallible comic touch.

From The Wall Street Journal • Jan. 13, 2026

His pizzazz was a large measure of his appeal, along with his manufactured image as a shrewd businessman with a kingly touch and infallible judgment.

From Los Angeles Times • Jan. 4, 2026

“It is this denial,” he announced, “that has plunged the prince deep into the melancholy of love. Fasting, brooding, sighing, and disordered dress are its most infallible signs.”

From "Ophelia" by Lisa Klein

Vocabulary lists containing infallible

The Vocabulary.com Top 1000

Looking to grow your vocabulary? Check out this interactive, curated word list from our team of English language specialists at Vocabulary.com – one of over 17,000 lists we've built to help learners worldwide!

ASVAB Word Knowledge

Interested in learning more words like this one? Our team at Vocabulary.com has got you covered! You can review flashcards, quiz yourself, practice spelling, and more – and it's all completely free to use!

"The Odyssey" by Homer, Books 1–7

Want to remember this word for good? Start your learning journey today with our library of interactive, themed word lists built by the experts at Vocabulary.com – we'll help you make the most of your study time!