noun

1. The superior or head of an abbey.
2. One of a class of bishops whose sees were formerly abbeys. Encyc. Brit.

example

Abbot of the people. a title formerly given to one of the chief magistrates in Genoa.
Abbot of Misrule (or Lord of Misrule), in medival times, the master of revels, as at Christmas; in Scotland called the Abbot of Unreason. Encyc. Brit.