Source : Webster's Revised Unabridged Dictionary (1913)

Oversight \O"ver*sight`\, n.
   1. Watchful care; superintendence; general supervision.

   2. An overlooking; an omission; an error. --Hooker.

   3. Escape from an overlooked peril. [R.] ``His fool-happy
      oversight.'' --Spenser.

   Syn: Superintendence; supervision; inspection; overlooking;
        inadvertence; neglect; mistake; error; omission.

Source : WordNet®

oversight
     n 1: an unintentional omission resulting from failure to notice
          something [syn: {inadvertence}]
     2: management by overseeing the performance or operation of a
        person or group [syn: {supervision}, {supervising}, {superintendence}]
     3: a mistake resulting from inattention [syn: {lapse}]