antipope

• anti-pope

From Middle French antipape (later assimilated to anti- +‎ pope), from Medieval Latin antipāpa.

• (UK) IPA^(key): /ˈantɪpəʊp/
• (General American) IPA^(key): /ˈæntiˌpoʊp/, /ˈænˌtaɪˌpoʊp/

antipope (plural antipopes)

1. (Christianity) A person who claims or claimed to be the pope, usually as the result of a disputed election or deposition, but is not considered by the Roman Catholic Church to be the real pope.
   • 2007, Edwin Mullins, The Popes of Avignon, Blue Bridge, published 2008, page 59:

     Meanwhile support for the ‘puppet’ antipope Nicholas V, deprived of his protector and by now excommunicated along with his emperor, rapidly withered away.

• antibishop
• pseudocardinal

• schism

•   antipope on Wikipedia.Wikipedia