wraps : The paper covering on the outside of a paperback.

jacket : Sometimes used as another term for dust jacket, a protective and often decorative wrapper, usually made of paper which wraps around the binding of a book

vg : Very Good condition. can describe a used book that does show some small signs of wear - but no tears - on either binding or paper. Any defects must be noted. (defined by AB Bookman's Weekly)

trade paperback : Often used to indicate any paperback book that is somewhat larger than a mass-market paperback.

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.