- Not fallible; not capable of erring; entirely exempt
from liability to mistake; unerring; inerrable. - Not liable to fail, deceive, or disappoint;
indubitable; sure; certain; as, infallible evidence; infallible
success; an infallible remedy. - Incapable of error in defining doctrines touching faith
or morals. See Papal infallibility, under Infallibility.