Definitions for "Endpaper"
The double leaf at the beginning and end of the book, one half adhered to board known as 'pastedown' other half known as 'free endpaper'
Sometimes called "endleaves," an endpaper is the double leaf at the very front and back of a book, half of which is pasted to the inside of the boards, the other half of which makes up the front and back free endpapers.
A sheet or sheets attached to the text block by the binder. The free endpaper is the extension of the paste-down.