Final answer:
The staff used by a bishop as a symbol of his office is known as a crosier or pastoral staff, representing the bishop's role as a shepherd to his spiritual flock and is often seen in historical depictions of religious figures and liturgical art.
Step-by-step explanation:
The name of the staff used by a bishop as a symbol of his office is called a crosier or pastoral staff. It signifies the bishop's role as a shepherd to his flock, leading and guiding them in spiritual matters.
The crosier typically looks like a stylized shepherd's crook and is an integral part of the bishop's regalia during liturgical services. These staffs are often richly decorated, reflecting the importance of the office.
In historical and liturgical contexts, we can see bishops depicted with crosiers as a sign of their authority and responsibility. For instance, in the Bayeux Tapestry, dating around 1070, Odo the Bishop is shown with a staff (baculum), which is a reference to the crosier.
Also, in liturgical art found in places like the bema of early churches, depictions of bishop saints holding crosiers often accompany other liturgical objects, reflecting their sacramental role and pastoral authority within the religious space and services.