This is the 10553rd most frequent Spanish word.
cremallera
Zipper.
In this example, 'cremallera' again refers to the zipper mechanism, this time specifically on a backpack.
Por favor, cierra la cremallera de tu mochila antes de salir.
Please close the zipper of your backpack before leaving.
In this sentence, 'cremallera' refers to the zipper mechanism used in clothing or other items to secure openings.
La cremallera de tu chaqueta está rota.
The zipper of your jacket is broken.
Here, 'cremallera' is used in a mechanical context to describe the rack part in a rack-and-pinion steering system.