To summon (a legal action) from a lower court to a higher court, especially the papal Court of Rome. Compare "advocate", "advocation".
Chiefly with reference to the legal matter of Henry VIII's divorce from Catherine of Aragon.
Mid 16th century. From Middle French advoquer to summon (a legal action) to a court, to summon, call upon from classical Latin advocāre. Compare earlier revoke, provoke, etc.