hardback

The word 'hardback' is a transparent compound formed from two native English elements. 'Hard' descends from the Proto-Germanic hardu-, itself from the Proto-Indo-European root kar- meaning "hard." 'Back' comes from Proto-Germanic bakam. The compound logically describes a book bound with rigid covers, as opposed to a flexible paperback. This practical term emerged in the 19th century to specify a durable binding style, directly linking the physical property ('hard') to the part of the book it modifies ('back' or cover).

Structure: hard (firm) + back (rear part) - hard: From Old English heard, meaning "solid, firm, not soft." It functions as an adjective describing the quality of the material. - back: From Old English bæc, meaning "the rear surface." It functions as a noun referring to the cover or spine of a book.