Game concept
Marriage
The game also links it as Married, Marry, Marries, Marriages, Marrying.
From the game's encyclopedia
Marriages are a union between two Spouses, and are (alongside Betrothals) the main way to forge an Alliance with another Ruler.
Spouses may also produce Legitimate children, who can be Bred and raised as suitable Heirs.
Marriages only end when one Spouse dies or Divorces the other.
Hosting a Grand Wedding greatly increases the acceptance of a Marriage proposal.
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.
Marriage is an entry of Crusader Kings III's in-game encyclopedia. The game explains it: "Marriages are a union between two Spouses, and are (alongside Betrothals) the main way to forge an Alliance with another Ruler." The game also links it as Married, Marry, Marries, Marriages and 1 more. 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.