unopened : A state in which all or some of the pages of a book have not been separated from the adjacent pages, caused by a traditional method for printing and binding books in which a large sheet of paper was printed with several pages, folded, and bound into the book. . Sometimes inappropriately called uncut

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.