paperback UK /ˈpeɪ.pə.bæk/US /ˈpeɪ.pɚˌbæk/adjective 1noun 1verb 1forms 3 adjective1 •Having flexible binding. noun1 •A book with flexible binding. verb1 •To issue or publish (a book) in a paperback edition. formspaperbacked · paperbacking · paperbacks