The New Century Dictionary in two volumes, published by Appleton Century, 1940s. These have some really nice color plates and TONS of small illustration engravings - but they'd also make great display pieces, risers, or just general vintage decor!
These measure 8" x 11", the stack of the two together is more than 5" thick. These have been much used in their time, and do show wear, and some water spotting. They smell fine, a good old book smell.