bind·er 
(bīndər)
(bīndər)n.
1. One that binds, especially a bookbinder.
2. Something, such as a cord, used to bind.
3. A notebook cover with rings or clamps for holding sheets of paper.
4. Something, such as the latex in certain paints, that creates uniform consistency, solidification, or cohesion.
5.
a. A machine that reaps and ties grain.
b. An attachment on a reaping machine that ties grain in bundles.
6. Law
a. A payment or written statement making an agreement legally binding until the completion of a formal insurance contract.
b. An agreement specifying the terms and conditions of a real estate transaction.
7. Ecology A plant, such as a ground cover, whose growth retards erosion.