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):

bookish
    adj 1: characterized by diligent study and fondness for reading;
           "a bookish farmer who always had a book in his pocket";
           "a quiet studious child" [syn: bookish, studious]

Moby Thesaurus II by Grady Ward, 1.0:

36 Moby Thesaurus words for "bookish":
   academic, autodidactic, bibliophagic, bluestocking, book-fed,
   book-learned, book-loving, book-minded, book-read, book-wise,
   booky, college-bred, collegiate, devoted to studies, diligent,
   donnish, dryasdust, graduate, highbrow, inkhorn, learned, literary,
   mandarin, owlish, pedantic, postgraduate, professorial, rabbinic,
   scholarly, scholastic, schoolboyish, schoolgirlish, sophomoric,
   studentlike, studious, undergraduate