hardbounds

/ˈhɑrdˌbaʊndz/
noun
  1. Books that have a rigid, stiff cover made of cardboard or cloth, as opposed to a flexible paper cover (paperback).
    • She bought the hardbounds of the entire series instead of waiting for the paperbacks.
    • I prefer hardbounds for my favorite novels because they look nicer on the shelf.
    • The library keeps all its reference books in hardbounds so they last longer.
Synonyms