locking device
nounUK /ˈlɒkɪŋ dɪˌvaɪs/
US /ˈlɑːkɪŋ dɪˌvaɪs/
A locking device is a thing that keeps a door or lid shut so it cannot open.
The gate has a locking device so the dog cannot get out.
OTHER MEANINGS
2. A mechanism that stops a machine or part from moving.
The machine has a locking device to keep the wheel still.
3. A safety part that holds something in place.
The car seat uses a locking device to stay secure.
4. A small tool or clip that keeps a box closed.
She put a locking device on the toolbox.