CEFR C1
infallible
adjective
Meaning
Incapable of making mistakes or being wrong; absolutely trustworthy or certain.
Examples
- Even the most experienced surgeons are not infallible; errors can sometimes occur.
- Many people believe that the legal system should be infallible, but human judgment is always involved.
Synonyms: unerring, unmistakable, flawless, impeccable