Triple-decker
noun·Victorian
A novel published in three separately bound volumes — the dominant format for serious British fiction from the 1820s through the 1890s.
A novel published in three separately bound volumes, the dominant format for serious British fiction from the 1820s through the 1890s. Circulating libraries like Mudie's enforced the format because it allowed them to lend three different books to three different subscribers from a single title.