What is Defensor?

Legal Definition
In the civil law. A defender; one who assumed the defense of another's case in court. Also an advocate. A tutor or curator. In canon law. The advocate or patron of a church. An officer who had charge of the temporalities of the church. In old English law. A guardian, defender, or protector. The defendant in an action. A person vouched in to warranty.
See also
-- Black's Law Dictionary
Legal Definition
A defendant; a guardian.
-- Ballentine's Law Dictionary