Definitions of latch:

• noun:   catch for fastening a door or gate; a bar that can be lowered or slid into a groove
• noun:   spring-loaded doorlock that can only be opened from the outside with a key
• verb:   fasten with a latch

  Example: "Latch the door"

• name:  A surname (rare: 1 in 100000 families; popularity rank in the U.S.: #17692)