July 20, 2004 Protestant Poll: Protestant Majority in U.S. eroding Prot•es•tant   (pr t  -st nt) n.        1. A member of a Western Christian church whose faith and practice are founded on the principles of the Reformation, especially in the acceptance of the Bible as the sole source of revelation, in justification by faith alone, and in the universal priesthood of all the believers.        2. A member of a Western Christian church adhering to the theologies of Luther, Calvin, or Zwingli. adj. Of or relating to Protestants or Protestantism. --If you don’t adhere to the definition of Protestantism, don’t call yourself one; you’re only demeaning yourself.