The act of getting a book out on the train, tube bus or plane in order to avoid talking tothe person next to you. Substitutes include a newspaper, phone or iPod.
Person one: "Blablabla isn't the weatherterrible blablabla"
Person two: (gets book out thus giving Person one "The book off")
Person one stops talking.
An adjective to refer to something of incredible value. A deal so ludicrous that it makes you wonder how a store could possibly be profiting from selling a product at such a low amount. The term originates from the second hand store chain in Japan known by the same name.
Person1: 10$ for 30 mint condition volumes of manga!? How is this even possible?
Person2: Yeah man, that's quite the Book Off deal.