WordNet (r) 3.0 (2006):

trade book
    n 1: a book intended for general readership [syn: trade book,
         trade edition] [ant: school text, schoolbook, text,
         text edition, textbook]

Moby Thesaurus II by Grady Ward, 1.0:

53 Moby Thesaurus words for "trade book":
   back number, best seller, book, bound book, classic, collection,
   coloring book, copy, definitive work, edition, folio, great work,
   hardback, impression, issue, juvenile, juvenile book, library,
   library edition, limp-cover book, magnum opus, nonbook, notebook,
   novel, number, opus, opuscule, opusculum, paperback, picture book,
   playbook, pocket book, prayer book, printing, production,
   psalmbook, psalter, publication, school edition, serial, series,
   set, sketchbook, soft-cover, songbook, standard work, storybook,
   title, tome, trade edition, volume, work, writing