1. Relating to or characteristic of a member of an upper governing body: As a new senator, Mrs. Johnson was granted senatorial privileges.
2. A reference to those who are part of an upper legislative group: The university students were invited to visit their state senators in their senatorial offices.

A custom in which presidential appointments are confirmed if there is no objection to them by the two members of the upper house of the United States Congress who are from the appointee's state: The president’s choices of a federal district court judge, a U.S. attorney, and a federal marshal for the two senators' state was approved via the process of senatorial courtesy because there was no objection to the appointees.