The rough edge on an untrimmed sheet of hand-made paper. The deckle is the frame on a paper-making mold. Often found in older books and manuscripts whose leaves have not been cut or trimmed. It may also be spelled without the hyphen.
Geoffrey Ashall Glaister. Encyclopedia of the Book, 2nd ed. (New Castle, DE: Oak Knoll Press; London: The British Library, 1996).