Noah Webster's Dictionary 1. (a.) Not capable of erring; entirely exempt from liability to mistake; unerring; inerrable. 2. (a.) Not liable to fail, deceive, or disappoint; indubitable; sure; certain; as, infallible evidence; infallible success; an infallible remedy. 3. (a.) Incapable of error in defining doctrines touching faith or morals. See Infallibility.

Multi-Version Concordance Infallible (1 Occurrence) Acts 1:3 To whom also he shewed himself alive after his passion by many infallible proofs, being seen of them forty days, and speaking of the things pertaining to the kingdom of God: (KJV WBS)