What does ADVOCATI FISCI mean? March 24, 2017 All Dictionary ADVOCATI FISCI meaning in Law Dictionary in civil law. Supporters regarding the fiscs or income; financial advocates, (qui causam fisct egisscnt.) Cod. 2, 9, 1; Id. 2. 7, 13. Answering, in a few measure, into the king's counsel in English law. 3 Bl. Comm. 27.