latch

1. N-COUNT A latch is a fastening on a door or gate. It consists of a metal bar which you lift in order to open the door. 门闩

You left the latch off the gate and the dog escaped. 你没插门闩，狗跑了。

2. N-COUNT A latch is a lock on a door which locks automatically when you shut the door, so that you need a key in order to open it from the outside. 弹簧锁

...a key clicked in the latch of the front door. …钥匙在前门的弹簧锁里发出咔哒的声响。