a book with paper covers
"I found the novel at a discount because it was sold as an inexpensive paperback rather than a hardcover edition."
A book with flexible binding.
"I prefer reading my favorite novels in paperback because the flexible binding makes them easy to hold while traveling."
In plain English: A paperback is a thin book with flexible covers made of paper instead of hard cardboard.
"I bought a cheap paperback version of the novel to read on my vacation."
Usage: Use paperback to refer specifically to a softcover book with flexible pages and binding, distinguishing it from hardcover editions. This term applies regardless of whether the book is new or used, provided it lacks rigid protective covers.
To issue or publish a book in paperback
"The publisher decided to release the bestseller as a paperback next month so more readers could afford it."
In plain English: To paperback something means to put a book into a soft cover for protection.
"The author decided to paperback her latest story for a quick read."
Usage: Paperback is strictly a noun referring to a softcover book and should never be used as a verb. Instead, use phrases like "publish in paperback" or "release as a paperback" to describe the action of issuing a book with this binding.
(of books) having a flexible binding
"She carefully folded the corner of her worn paperback to mark where she left off in the novel."
Having flexible binding.
"I prefer reading on a park bench because my favorite novel has a paperback cover that won't crack like a hardcover does."
In plain English: A paperback is an adjective used to describe a book with flexible, soft covers instead of hard ones.
"She prefers reading a paperback mystery novel on her train ride home."
Usage: Use "paperback" as an adjective to describe books with flexible bindings that are cheaper and thinner than hardcovers. It specifically refers to the type of book cover rather than the material content or size alone.
The word paperback combines the materials it is made from with its format to describe books bound in flexible covers rather than hard ones. It evolved as a shortened form of the earlier phrase "paper-backed book."