subsidence; sinking; cave-in; collapse; falling in
fall (of a city, fortress, etc.); surrender
fall (in position, rank, etc.); demotion
giving in (to someone's persuasion); yielding; being convinced
要塞は長い包囲戦の末に陥落を免れなかった。
The fortress could not avoid falling after a long siege.
城が敵軍の攻撃で陥落した。
The castle fell to the enemy's attack.
首都の陥落は戦争の転機となった。
The fall of the capital became a turning point in the war.