Game concept
Embrace Celibacy
The game also links it as Embrace Celibacy Decision.
From the game's encyclopedia
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.
Embrace Celibacy is an entry of Crusader Kings III's in-game encyclopedia. The game explains it: "A Decision that allows a character to gain the Celibate Trait at will." It is part of Decision. The game also links it as Embrace Celibacy Decision. Patch 1.20.1.2, from game/common/game_concepts/00_game_concepts.txt and game/localization/english/game_concepts_l_english.yml.
Source: game/common/game_concepts/00_game_concepts.txt, game/localization/english/game_concepts_l_english.yml and the English localisation, Crusader Kings III 1.20.1.2.