The Collaborative International Dictionary of English v.0.48:

Ignorance \Ig"no*rance\, n. [F., fr. L. ignorantia.]
   1. The condition of being ignorant; the lack of knowledge in
      general, or in relation to a particular subject; the state
      of being uneducated or uninformed.
      [1913 Webster]

            Ignorance is the curse of God,
            Knowledge the wing wherewith we fly to heaven.
                                                  --Shak.
      [1913 Webster]

   2. (Theol.) A willful neglect or refusal to acquire knowledge
      which one may acquire and it is his duty to have. --Book
      of Common Prayer.
      [1913 Webster]

   Invincible ignorance (Theol.), ignorance beyond the
      individual's control and for which, therefore, he is not
      responsible before God.
      [1913 Webster]

WordNet (r) 3.0 (2006):

ignorance
    n 1: the lack of knowledge or education