What is Extrajudicial?

Legal Definition
That which does not belong to the judge or his jurisdiction, notwithstanding which he takes. cognizance of it. Extrajudicial judgments and acts are absolutely void. Vide Coram non judice, and Merl. Repert. mots Exces de Pouvoir.
-- Bouviers Law Dictionary
Legal Definition
That which is done, given or effected outside the course of regular Judicial proceedings; not founded upon or unconnected with, the -action of a court of law; as extrajudicial evidence, an extrajudicial oath. That which, though done in the course of regular judicial proceedings, is unnecessary to such proceedings, or interpolated, or beyond their scope; as an extrajudicial opinion, (dictum.) That which does not belong to the judge or his jurisdiction, notwithstanding which he takes cognizance of it.
See also
-- Black's Law Dictionary
Legal Definition
Without jurisdiction.
-- Ballentine's Law Dictionary