lock down

verb

They lock down the building every night for security purposes.

意味（1）

(transitive) To secure; to make people stay locked indoors for their safety.

Police have the area locked down until the situation is all-clear.

意味（2）

(transitive) To limit the use of a computer network to only users with permission.

意味（3）

(transitive) To make an arrangement secure, definite, or permanent; to fix.

意味（4）

(transitive, slang) To cause another to enter into an exclusive romantic relationship.

It took me some time, but I finally locked her down.

意味（5）

(intransitive, boating) To travel through a flight of locks on a waterway in a downhill direction.