Refers to the state of being under house arrest or confined, often used in legal, political, or dramatic contexts.
He is under house arrest at his home.
The confinement continues, and I can't go outside.
軟禁 is the act of placing someone under house arrest; 軟禁状態 emphasizes the resulting state or condition.
監禁 is a broader term for imprisonment or confinement, not necessarily at home.
Compound of 軟禁 (house arrest) and 状態 (state, condition).