a machine that cuts grain and binds it in sheaves
"The farmer used an old binder to harvest the wheat and tie it into neat sheaves for storage."
something used to bind separate particles together or facilitate adhesion to a surface
"The binder in the concrete mix helps hold the sand and gravel particles together."
holds loose papers or magazines
"She placed her collection of vintage magazines into a sturdy binder to keep them organized and protected from dust."
Someone who binds
"The ancient binder carefully tied the loose scrolls together before placing them on the shelf."
A surname.
"The local historian wrote an article about the famous mathematician John Binder, noting that his family name is of German origin."
The word binder comes from Middle English byndere, which was formed by adding the suffix -er to the verb bind. It originally referred to a person or thing that binds, maintaining this core meaning as it entered modern usage.