Game concept
House Unity
The game also links it as Unity.
From the game's encyclopedia
House Unity represents the state of internal relationships within a Clan House, and the attitude members have towards each other.
There are several House Unity Levels, which provides the members of a House with various benefits and penalties.
House Unity changes depending on the actions House members take towards one another. Unifying Actions will generally increase House Unity, while Divisive Actions will decrease it. The House Head generally have a greater degree of influence over their House's Unity.
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.
House Unity is an entry of Crusader Kings III's in-game encyclopedia. The game explains it: "House Unity represents the state of internal relationships within a Clan House, and the attitude members have towards each other." The game also links it as Unity. Patch 1.20.1.2, from game/common/game_concepts/03_fp3_game_concepts.txt and game/localization/english/game_concepts_l_english.yml.
Source: game/common/game_concepts/03_fp3_game_concepts.txt, game/localization/english/game_concepts_l_english.yml and the English localisation, Crusader Kings III 1.20.1.2.