A mook /mʊk/ is a publication which is physically similar to a magazine but is intended to remain on bookstore shelves for longer periods than traditional magazines.
The term is a portmanteau of "magazine" and "book". It was first used in 1971, at a convention of the Fédération Internationale de la Presse Périodique. The format has become particularly popular in Japan, where several fashion designers publish "brand mooks" to promote their products.
American examples of mooks include Make and Craft.
References
Mook (publishing) Wikipedia(Text) CC BY-SA