spine : The outer portion of a book which covers the actual binding. The spine usually faces outward when a book is placed on a shelf. Also known as the back.

price clipped : The portion of the dust jacket flap where the publisher prints the suggested price has been cut away. Usually this is a clean 1-2" diagonal cut made with scissors.

4to : Or quarto. A term used generally to describe the approximate size of a book, a book that is about 10" to 12" tall and roughly squarish in shape. The term is based on the size of paper traditionally used by book printers which has been folded and cut into 16 pages.

Cloth : Generally refers to a hardcover with cloth covering the outside of the book covers.