In Latin, the verb “arrogāre” has several usages. It can mean “to appoint along with (another magistrate),” but it can also mean “lay claim to,” “claim to possess,” “make undue claims,” or “be conceited.” These alternative meanings carry through to the English word “arrogate,” which can mean “to claim without justification,” “to make undue claims to possession,” or “to claim on behalf of another.” If you use the word “arrogate” when describing a situation, there’s an undeserved or unearned claim going on.