noun
Etymology: translation of New Latin advocatus diaboli
1. Roman Catholicism : an official of the Congregation of Rites whose duty is to point out defects in the evidence upon which a demand for beatification or canonization rests or in the character of the person for whom the honor is sought — called also promoter of the faith ; compare postulator
2. : a critic who picks flaws to evoke controversy or to bring out the whole truth
3. : a champion of the worse cause for the sake of argument