Infallibility: The characteristic of being completely trustworthy, incapable of erring or failing to accomplish an intended purpose. Protestants normally apply this characteristic to the Bible; Catholics extend infallibility to the magisterium (teaching authority) of the church. If one assumes that a purpose of the Bible is to communicate revealed truth, then infallibility logically implies at least limited inerrancy. Nevertheless, in practice some theologians affirm the infallibility but not the inerrancy of the Scriptures, intending thereby to indicate that the Bible can be relied on as an authority in matters of faith and practice while recognizing the possibility of scientific and historical errors.
C. Stephen Evans, Pocket Dictionary of Apologetics & Philosophy of Religion (Downers Grove, IL: InterVarsity Press, 2002), p. 60.