Game concept
Assault
The game also links it as Assaults, Assaulting, Assaulted.
From the game's encyclopedia
An Assault is when a Besieging Army attempts to storm a Fortified Holding at the risk of losing a lot of Soldiers. Assaults can only be attempted if the walls of the Holding have been Breached, which requires that the Army contains Siege Weapons.
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.
Assault is an entry of Crusader Kings III's in-game encyclopedia. The game explains it: "An Assault is when a Besieging Army attempts to storm a Fortified Holding at the risk of losing a lot of Soldiers." The game also links it as Assaults, Assaulting and Assaulted. 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.