latch

A latch is a device that holds two things together, like a door and its frame. It's usually something you can turn or lift to open or close something.

You see latches all around you - on doors, drawers, and even some gates. A latch might be a simple metal piece that you turn with your hand, or it could be more complicated, like a lock with a key. When you're using a door with a latch, you'll often find a handle to pull down or lift up to open the door. Sometimes, people say "latch" when they mean a mechanism that keeps something shut, so if someone says "Don't let it latch," they probably want you to keep an eye on whatever is moving in case it gets stuck.

Note: In some places, especially with electronic devices or machinery, people use the word "latch" as a verb, meaning to engage or activate something. For example, "Latching onto the signal" means grabbing hold of it, so it can be used. This usage is more technical and less common in everyday conversation.