Every fashionista worth her Louboutins cares as much about a book's outfit as she does about its content. This pursesized encyclopedia dons a cloth cover stamped with shimmering silver foil and a satin-ribbon page marker. Alongside vibrant illustrations, a team of fashion forecasters defines more than 285 terms from acid wash to zebra (fatigues are really just exhausted clothes) and answers sartorial quandaries (What do I do when I've bought a genuine...