adjective /ˈbʊk.ɪʃ/
a) Given to reading; fond of study; better acquainted with books than with people; learned from books.
From a child I was fond of reading, and all the little money that came into my hands was ever laid out in books. This bookish inclination at length determined my father to make me a printer, though he had already one son (James) of that profession.
b) Characterized by a method of expression generally found in books.
Obviously, neither Corneille nor the characters who laugh at excessively bookish speech avoid literary convention.
Wikipedia foundation.