Definition of "protectorate"

Government by a protector; especially, the government of England, Scotland, and Ireland by Oliver Cromwell.  examples

The authority assumed by a superior power over an inferior or a dependent one, whereby the former protects the latter from invasion and shares in the management of its affairs but the protected state retains its nominal sovereignty.  examples

An autonomous territory that is protected diplomatically or militarily against third parties by a stronger state or entity.  examples