Pins are very small thin pointed pieces of metal. They are used in sewing to fasten pieces of material together until they have been sewn.

If you pin something on or to something, you attach it with a pin, a drawing pin, or a safety pin.

A pin is any long narrow piece of metal or wood that is not sharp, especially one that is used to fasten two things together.

If someone tries to pin something on you or to pin the blame on you, they say, often unfairly, that you were responsible for something bad or illegal.

If you pin your hopes on something or pin your faith on something, you hope very much that it will produce the result you want.

If someone pins their hair up or pins their hair back, they arrange their hair away from their face using hair pins.

A pin is something worn on your clothing, for example as jewellery, which is fastened with a pointed piece of metal.

A pin is the part of a hand grenade that is pulled out in order to make the grenade explode.

You can say you could have heard a pin drop when a place is extremely quiet, especially because everyone is waiting for someone to speak or when someone has made a shocking remark.