infallible
UK: ɪnˈfæləbl̩ | US: ɪnˈfæləbl̩
adj. incapable of making mistakes or being wrong
adj. never failing; always effective
The word "infallible" originates from Latin infallibilis, combining the negative prefix in- (not) with fallere (to deceive or fail) and the suffix -ibilis (able to). The root fall retains its core meaning of "failure" or "error," while -ible denotes capability. Over time, the term evolved to describe absolute reliability or impossibility of error, often used in theological or authoritative contexts.
The scientist claimed his method was infallible, yet errors soon appeared.
Many believers consider the pope infallible in matters of doctrine.
No system is truly infallible under extreme conditions.
Her infallible memory made her the best candidate for the job.
The machine’s infallible accuracy saved countless hours of manual work.