Chief justiciar
Black's Law Dictionary · Henry Campbell Black, M.A. · 1910
Black's Law Dictionary
In old English law
A high judicial officer and special magistrate, who presided over the aula regis of the Norman kings, and who was also the principal minister of state, the second man in the kingdom, and, by virtue of his office, guardian of the realm in the king's absence.
3 Bl. Comm. 38.