The Collaborative International Dictionary of English v.0.48:

donnish \donnish\ adj.
   like a university don; marked by a narrow focus on or display
   of learning, especially its trivial aspects.

   Syn: academic, pedantic, bookish.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

donnish
    adj 1: marked by a narrow focus on or display of learning
           especially its trivial aspects [syn: academic,
           donnish, pedantic]