Game concept
Contribution
The game also links it as Contributes, Contributions.
From the game's encyclopedia
A Modifier may change the Contribution of your Vassals Obligations. This is not the same as Base Contribution.
If you have a Vassal that pays you 1 Gold per month, and you gain a Modifier that increases Contribution by 10%, then the Vassal instead pays you 1.1 Gold.
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.
Contribution is an entry of Crusader Kings III's in-game encyclopedia. The game explains it: "A Modifier may change the Contribution of your Vassals Obligations." The game also links it as Contributes and Contributions. 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.