Merriam-Webster Logo
SINCE 1828
Menu
×

An Encyclopædia Britannica Company

Thesaurus

infallible

adjective

Synonyms and Antonyms of infallible

  1. 1 not being or likely to be wrong a teacher with an infallible memory for names Synonyms unerring, unfailing Related Words errorless, faultless, flawless, impeccable; certain, foolproof, inerrant, perfect, sure; dependable, reliable Near Antonyms defective, faulty, flawed, imperfect; undependable, unreliable Antonyms fallible

  2. 2 not likely to fail an infallible cure for hiccups Synonyms can't-miss, certain, fail-safe, sure, surefire, unfailing Related Words dependable, reliable; deadly, unerring Near Antonyms doubtful, questionable, uncertain Antonyms fallible

Explore Merriam-Webster

alt-59760690a61d7
Trending: Trump Tweets, We Define: 'Beleaguered'
image386126722
Words That Come From the Dinner Table
video-title-words-of-the-year-1066
Words of the Year: 1066
emoji-the-quiz
The Emoji Quiz

Learn More about infallible

  1. Dictionary: Definition of infallible Spanish Central: Translation of infallible Nglish: Translation of infallible for Spanish speakers Britannica English: Translation of infallible for Arabic speakers

Seen and Heard

What made you want to look up infallible? Please tell us where you read or heard it (including the quote, if possible).

show hide

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

WORD OF THE DAY

haphazard

play

marked by lack of plan or order

Get Word of the Day daily email!

TRENDING NOW

  1. beleaguer 'Being subjected to constant or repeated trouble or harassment'

  2. scaramouch A new White House communications director

  3. non sequitur “It does not follow”

  4. admiral's mast A massive search ends with an 'admiral's mast'.

  5. calumny 'An untrue statement that is made to damage someone's reputation'

SEE ALL

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

Words at Play

alt-596f95fe451e7
'Drought' & 'Drouth' Take Us Back In Time

A variant spelling with a long history

alt-59721dd897313
The 'Best' Way to Sign Off On An E-mail

Give them your best

image386126722
Words and Phrases That Come from the Dinner Table

Fill your plate with these surprising food words

ghost-being-disinvited-from-party
'Disinvite' or 'Uninvite'?

A disinvited guest is an uninvited problem

Ask the Editors

video-title-words-of-the-year-1066
Words of the Year: 1066

Or, Why Pig Meat is Called 'Pork' and Cow Meat is Called 'Beef'

payday
How Often Is 'Biweekly'?

Don't get us started on 'bimonthly'

video-irregardless-grammar-peeve-blend-of-the-synonyms-irrespective-and-regardless
Irregardless

It is in fact a real word (but that doesn't mean you should use it).

video-moose-goose-weird-plurals
Weird Plurals

One goose, two geese. One moose, two... moose. What's up with that?

Word Games

emoji-the-quiz
The Emoji Quiz

Think you’re an emoji 👓 expert? Let’s see 🤔

Take the quiz
image941935269
A Game of Thrones Word Quiz

In the Game of Thrones quiz, you learn some new vocabulary. (It’s quite safe, really. You will not die.)

Take the quiz
How Strong Is Your Vocabulary?
How Strong Is Your Vocabulary?

Test your vocabulary with our 10-question quiz!

Take the quiz
SCRABBLE® Sprint
SCRABBLE® Sprint

SCRABBLE® fans, sharpen your skills!

Play the game