Fastener has 3 different meanings across 1 category:
Noun
a person who fastens or makes fast
"he found the door fastened and wondered who the fastener was"
restraint that attaches to something or holds something in place
"She tightened the plastic fastener on her backpack before climbing onto the bus."
Something or someone that fastens.
"The old machine's broken fastener refused to hold the metal plates together, forcing me to find a replacement before I could finish building the shed."