Publishing. In singular and (esp.) in plural. The unsold copies of an edition of a book for which demand has fallen, often sold at a reduced price…
An old or unsaleable book.
General attributive (in sense A. 7), as remainder book, remainder list, remainder shop, etc.
slang (originally North American). Publishing. A book which sells badly; a remainder.
A book returned unsold by a bookseller to the publisher.
A book distinguished commercially by its low sales; (also) the writer of such a book; opposed to bestseller, n.