Well, exo- means “outside” and xeno- means “foreign/alien”, so they both convey the same meaning. In any case, exo- is the opposite of endo- (inside) and auto-

Well, exo- means “outside” and xeno- means “foreign/alien”, so they both convey the same meaning. In any case, exo- is the opposite of endo- (inside) and auto- (self) could be perceived as the opposite of xeno-, so I would pair the antonyms as: endonym/exonym and autonym/xenonym.