The definition of disenfranchised is having had your rights or privileges taken away, or being deprived of the chance to vote.(adjective)
Felons who are no longer allowed to vote in elections are an example of people who would be described as disenfranchised.
Disenfranchised is defined as the act of having taken away someone's right to vote, or of having deprived the person of their privileges or rights.(verb)
When the legislature passed a law saying that felons could not vote, this is an example of a time when the legislature disenfranchised felons.