Fastener (noun)

A device or material used to secure two or more objects together.

Origin:

From the verb 'to fasten' meaning 'to secure or fix in place'.

Examples:

1. The fastener held the book cover in place, as the pages inside were turned.
2. The fastener on the back of the necklace was broken, and the pendant fell off.
3. The fastener on the door was a simple latch, which could be easily unlocked.
4. The fastener for the car seat belt was adjusted to fit the driver's size.
5. The fastener for the curtains was a hook and eye, which could be opened and closed easily.