Someone that steals books. This word is fairly useless as it is two syllables longer than "book thief", which makes more sense than saying this long ass word.
Jake: Look, I have heard that guy is a Biblioklept. Even he doesn't know how many books he has stolen.
James: We cant blame him. Its just because he loves to read.
The student and librarian were hospitalized with broken ribs as a result of the biblioleptoppary, and couldn't recover their knickers until the following week.