Definition of binders:
(n) :
Someone who binds.
(n) :
Someone who binds books; a bookbinder.
(n) :
A cover or holder for unbound papers, pages, etc.
(n) :
Something that is used to bind things together, often referring to the mechanism that accomplishes this for a book.
(n) :
(programming) A software mechanism that performs binding.
(n) :
(computing) A program or routine that attaches malware to an existing harmless file on the target system.