n. A person who claims or claimed to be the pope as the result of a disputed election, but is not considered by the Roman Catholic Church to be the real pope.
the GNU version of the Collaborative International Dictionary of English
n. One who is elected, or claims to be, pope in opposition to the pope canonically chosen; esp. applied to those popes who resided at Avignon during the Great Schism.
The Century Dictionary and Cyclopedia
n. One who usurps or is elected to the papal office in opposition to a pope held to be canonically chosen.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
n. someone who is elected pope in opposition to another person who is held to be canonically elected
Word Usage
"Amadeus VIII (1391-1434), known as the antipope Felix V (q. v.), was made a duke by Emperor Sigismund in 1416; in 1422 he received the"