(see also: glossary)
Any reputable book seller will add to their description of a book with details of any faults. The English language is quite versatile so there are many, many ways to describe a book’s condition. Below are some of the most commonly used descriptors (in conjunction with the condition grades).
BOWED: Also sometimes referred to as distorted. This is when the board covers of a hardback book have curled in or out, often because of changes in humidity.
BINDING COPY: This refers to a book who’s pages are complete, including any illustrations, but the binding is very poor (loose, detached or missing).
BUMPING: Similar to edge-worn but more frequently used to refer to corners. This is often the result of how a book is stored.
CHIPPED: Usually applies to the cover of a book, whether hardback or paperback, and/or the dust jacket. It shows as small pieces missing from the edges.
DAMPSTAINED: This refers to small stains caused by moisture to the cover or on some pages, but it is not as extensive as water stains.

DARKENING/FADING: Usually caused by light which results in the colour becoming more vivid or faded.
EDGE-WORN: Light wear along the edges of the book cover and/or dust jacket.
EX-LIBRARY: A book which has previously been available in a public library. It will likely have stickers, labels and stamps and may have a “withdrawn” stamp accompanied by a handwritten price.
EX-LIBRIS: From the library of ... a previous private owner. This is usually indicated on a printed plate inside the front cover on the front endpapers. The previous owner's name may be hand written or printed.
FOXED/FOXING: Foxing is the brown spots frequently found in old books as the result of a chemical reaction. It may be described as: Heavy, light, moderate, sporadic, profuse.
LOOSE: This refers to the binding which is often tight on a new book but becomes loose when a book is well read.
MADE-UP COPY: This refers to the marriage of different parts of the same book made up and bound from defective copies.
PRICE CLIPPED: Many books with dust jacket include the published price on the front flap (usually the top or bottom corner). A book which is price clipped has had that corner cut away.
READING COPY: Usually in poor condition, sometimes fair, this is a book which is complete but might only be desirable for reading.
RE-BACKED: A book which has had its spine and hinges replaced.
RE-CASED: A book which has previously become detached from its cover and has now been re-gummed in place
RE-JOINTED: A book which has been repaired within its original spine and covers.
RE-BOUND: This often applies to antiquarian books and refers to the complete replacement of the cover, spine and hinges.
RUBBING: Usually manifests as light surface marks on a book cover or dust jacket, caused by rubbing against other books or objects.
SEALED: Refers to a book which, when published, was enclosed in a sealed covering (usually clear polythene/plastic).
SHAKEN: A book who’s pages are coming loose from the spine.
SHELF WEAR: Usually fairly light wear which results from storing a book on a shelf. It frequently affects the bottom edges and corners and is the result of sliding a book into place. Conversely, the top of the spine may be affected from withdrawing a book from a shelf.
SUNNED: Often effects book spines, sometime the covers, and is the result of direct sunlight which causes fading.
TANNING: This affects the pages of a book when the paper takes on a brown hue. It is often more apparent on the endpapers.
TEARS/TORN: Self explanatory: Usually referring to the dust jacket or pages. Sellers will normally give some idea of the length of any tears.
TIGHT: This refers to the binding of a book, usually new, and indicates that the book pages will not lay flat when the book is opened.
TRIMMED: Suggests the pages have been trimmed and are now smaller than when the book was published
UNOPENED: The pages are still joined, usually along one edge.
UNTRIMMED: Some older books have one, two or three edges which are uneven. These are untrimmed pages and should be left as they are.
WATER STAINED: Water stains are usually more widespread than damp stains and will likely affect large parts of the cover or pages of a book.
WORKING COPY: Similar to a reading copy, hence in poor condition. Such a book will likely need to be re-bound before reading
WORMING/WORMHOLES: Bookworms are something of a scourge for collectors. Often caused by the larvae of beetles or insects such as silverfish, wormholes are small holes in the pages or cover of a book.
Booksellers often use what seems like a completely different language when describing a book, particularly when outlining format and size. I'll cover such things in later posts.