Late 16th century (in an earlier sense). From (i) post-classical Latin perioeci (plural) people dwelling at the same latitude but at the opposite or a different meridian and its etymon (ii) ancient Greek περίοικοι neighbours, inhabitants of dependent towns, subjects, especially of Sparta or Crete, in Hellenistic Greek also people dwelling at the same latitude but at the opposite or a different meridian, use as noun of plural of περίοικος, lit. ‘dwelling round, neighbouring’ from περι- + οἶκος house, dwelling.