Game concept
Cardinal
The game also links it as Cardinals, Cardinal's, Cardinals', Cardinalate, Cardinalates.
From the game's encyclopedia
A Clergy member selected by the Pope to help further exert the will of The Christian Church. All members of the College of Cardinals are both candidates and electors for the Papacy and have a Papabile Score.
The game's text for patch 1.20.1.2. Words in blue are entries of the encyclopedia: hover one to read it, as in the game.
Cardinal is an entry of Crusader Kings III's in-game encyclopedia. The game explains it: "A Clergy member selected by the Pope to help further exert the will of The Christian Church." It is part of rank. It covers College of Cardinals. The game also links it as Cardinals, Cardinal's, Cardinals', Cardinalate and 1 more. Patch 1.20.1.2, from game/common/game_concepts/pam_game_concepts.txt and game/localization/english/game_concepts_l_english.yml.
Source: game/common/game_concepts/pam_game_concepts.txt, game/localization/english/game_concepts_l_english.yml and the English localisation, Crusader Kings III 1.20.1.2.