Nonperson and Pariah

Nonperson noun - A person regarded as nonexistent and having no rights; a person whose existence is systematically ignored (especially for ideological or political reasons).

Pariah and nonperson are semantically related. In some cases you can replace term "Pariah" with "Nonperson", this nouns are similar.

Pariah noun - One who is cast out or rejected by society.

Nonperson and pariah are semantically related. Sometimes you can use "Nonperson" instead a noun "Pariah".