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.
3. One of the German princes and cities that supported the doctrines of Luther and protested against the decision of the second Diet of Speyer (1529) to enforce the Edict of Worms (1521) and deny toleration to Lutherans.
4. protestant (also pr-tstnt) One who makes a declaration or avowal.

1. often Fundamentalism An organized, militant Evangelical movement originating in the United States in the late 19th and early 20th century in opposition to Protestant Liberalism and secularism, insisting on the inerrancy of Scripture.
2. Adherence to the theology of this movement.

Protestant and Fundamentalist are also known as Bible Christians