Game concept
Sanctified
The game also links it as Sanctify, Sanctifying.
From the game's encyclopedia
Sanctifying an Artifact makes it a Holy Relic for a Faith. An artifact can be sanctified for multiple faiths.
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.
Sanctified is an entry of Crusader Kings III's in-game encyclopedia. The game explains it: "Sanctifying an Artifact makes it a Holy Relic for a Faith." It is part of Holy Site. The game also links it as Sanctify and Sanctifying. 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.