The Collaborative International Dictionary of English v.0.48:

Bookish \Book"ish\, a.
   1. Given to reading; fond of study; better acquainted with
      books than with men; learned from books. "A bookish man."
      --Addison. "Bookish skill." --Bp. Hall.
      [1913 Webster]

   2. Characterized by a method of expression generally found in
      books; formal; labored; pedantic; as, a bookish way of
      talking; bookish sentences.
      [1913 Webster] -- Book"ish*ly, adv. -- Book"ish*ness,
      n.
      [1913 Webster]

WordNet (r) 3.0 (2006):

bookishness
    n 1: exaggerated studiousness