Can refer to a person who passes something or an object that holds things together.
El pasador que usé para sujetar el cabello se me perdió en la fiesta.
The clip I used to hold my hair got lost at the party.
El pasador de la puerta estaba roto, por lo que tuvimos que reemplazarlo de inmediato.
The fastener of the door was broken, so we had to replace it immediately.