deaccessioningSelling or otherwise disposing of books from a collection.
deckle edgeRough edges which a sheet of paper has after it has left the deckle, but before it is trimmed in the papermaking process.
definitive editionThe most authoritative version of a work.
desideratum, pl. desiderataSomething needed and wanted. Desiderata is a want list.
double elephant folioDescription of the size of a book: about 50 inches high.
duodecimoDescription of the size of a book: about 7.75 inches high (12mo).
dust jacketThe paper cover (d.j.).
dust wrapperThe same as a dust jacket (d.w.).