Definition of infallible in English:

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Pronunciation: /inˈfaləb(ə)l/


1Incapable of making mistakes or being wrong: doctors are not infallible
More example sentences
  • Politicians must present themselves as infallible, incorruptible, incapable of dishonesty.
  • During the rest of the series, Trescothick has been infallible, and his reliability at first slip has improved England's out-cricket hugely.
  • It wasn't an altruistic thing at all, but she did believe deep in her heart that an infallible God, a God that would never steer her wrong, was telling her, requiring her to do that.
unerring, unfailing, faultless, flawless, impeccable, perfect, precise, accurate, meticulous, scrupulous
1.1Never failing; always effective: infallible cures
More example sentences
  • That we have no infallible technique does not mean that we are bound always to fail.
  • Price is not always an infallible guide to quality, though you would be very unlucky to find a poor-quality vintage champagne costing more than £40 a bottle.
  • I don't wish to trivialise a potentially fatal disease but received wisdom isn't always infallible, not even received medical wisdom.
unfailing, unerring, guaranteed, dependable, trustworthy, reliable, sure, certain, safe, foolproof, effective
informal sure-fire
formal efficacious
1.2(In the Roman Catholic Church) credited with papal infallibility: for an encyclical to be infallible the Pope must speak ex cathedra
More example sentences
  • The council's careful balancing of papal and episcopal authority did not seem intended to expand the church's infallible teaching to areas like contraception.
  • The church has proclaimed as infallible two dogmas in relation to Mary - the Immaculate Conception and the Assumption.
  • Unlike church dogma, encyclicals are not infallible pronouncements, but Catholics are expected to follow them, while the declaration of the papal view limits the freedom of theological discussion.



Pronunciation: /inˈfaləblē/
Example sentences
  • The students, always and infallibly observant of teachers' shortcomings, managed to ask her a few worried questions.
  • Healing always takes place, infallibly, one hundred percent of the time.
  • To repeat this indefinitely, infallibly, would be to divorce the method from the context which gives it meaning.


Late 15th century: from French infaillible or late Latin infallibilis, from in- 'not' + Latin fallere 'deceive'.

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Syllabification: in·fal·li·ble

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