DJ : Short for dust jacket, a protective and often decorative wrapper, usually made of paper which wraps around the binding of a 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.

bumped : Indicates that the affected part of the book has been impacted in such a way so as to cause a flattening, indention, or light bending.

VG/VG : Very Good Condition book with a Very Good Condition dust jacket. Very Good Condition indicates a used book that does show some small signs of wear - but no tears - on either binding or paper. Any defects must be noted. (as defined by AB Bookman's Weekly).