Game concept
Terrified
From the game's encyclopedia
Terrified Characters are paralyzed by fear of another character and will rarely take any hostile actions against that character, including starting Factions.
Characters are Terrified or Intimidated by Dread and/or a cowardly personality.
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.
Terrified is an entry of Crusader Kings III's in-game encyclopedia. The game explains it: "Terrified Characters are paralyzed by fear of another character and will rarely take any hostile actions against that character, including starting Factions." It is part of Dread. 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.