off limits
成語所屬單字limits
off limits — 慣用語
1. Not allowed to be entered, visited, used, or discussed because of a rule or rest
1.慣用語
釋義
禁止進入；不得使用
Not allowed to be entered, visited, used, or discussed because of a rule or restriction.
例句
The construction site was off limits to everyone except the workers wearing hard hats and safety vests.
During the exam, all mobile phones were strictly off limits for students in the testing room.