Gavin Ambrose & Paul Harris 
Visual Dictionary of Typography [PDF ebook] 

The Visual Dictionary of Typography is a guide to the many and varied terms used within typography. Arranged alphabetically from abstraction to x-height and blackletter to widow, each term is explained and contextualized with illustrations. More than 250 typographical terms are included. From practical terms such as accents, bitmap and classification to movements and styles such as constructivism, De Stijl, modernism and Swiss typography, this book contains both modern terminology and traditional terms still in current usage. The Visual Dictionary of Typography is an easy-to-use reference that will prove invaluable to anyone interested in typography and graphic design.