What does the word latch mean?

Usage examples for latch

  1. She watched the latch. – The Box with the Broken Seals by E. Phillips Oppenheim
  2. It was an ordinary wooden gate and it opened with a thumb latch. – The Window at the White Cat by Mary Roberts Rinehart
  3. I lifted the great latch and entered. – The Seaboard Parish, Complete by George MacDonald