[Vocabulary] pariah vs outcast

[Yonsu99]

The definitions and examples give me the impression that they are very much alike. Are they interchangeable synonyms? Or are there any differences to differentiate them?

pariah
If you describe someone as a pariah, you mean that other people dislike them so much that they refuse to associate with them.
His landlady had treated him like a dangerous criminal, a pariah.

outcast
An outcast is someone who is not accepted by a group of people or by society.
He had always been an outcast, unwanted and alone
Source:Collins Cobuild Advanced Learner's English Dictionary

 

[MikeNewYork]

Yes, they are synonyms.