Game concept
Truce
The game also links it as Truces.
From the game's encyclopedia
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.
Truce is an entry of Crusader Kings III's in-game encyclopedia. The game explains it: "Every War ends with a Truce; a period when the Attacker may not declare War again on that same Ruler (the Defender is not bound by the Truce)." The game also links it as Truces. 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.