boards : Common term for the covers of a hardbound book.

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.

sunned : The affected portion of the book has been discolored from exposure to the sun.

8vo : Short for Octavo, A book whose page size is approximately 8-10 inches tall. The size is based on a sheet of paper 25 inches by 38 inches, the size of paper traditionally used by book printers, which has been folded and cut into 16 pages.. Unfortunately often misunderstood to mean 8 volumes.

half title : The leaf which appears just prior to the title page, and typically contains only the title of the book, although, at times, the author's name and/or other information may appear.

endpapers : The first and last two pages (verso and recto) from the front and back of a book.

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