The Collaborative International Dictionary of English v.0.48:

Oversee \O`ver*see"\, v. t. [imp. Oversaw; p. p. Overseen;
   p. pr. & vb. n. Overseeing.] [AS. ofers['e]on to survey, to
   despise. See Over, and See.]
   [1913 Webster]
   1. To superintend; to watch over; to direct; to look or see
      after; to overlook[2].
      [1913 Webster]

   2. To omit or neglect seeing; to overlook[5]. [archaic]
      --Spenser.
      [1913 Webster]

   3. To see unintentionally or unexpectedly; -- the visual
      analogy to overhear.
      [PJC]