Source : Webster's Revised Unabridged Dictionary (1913)

Dereliction \Der`e*lic"tion\, n. [L. derelictio.]
   1. The act of leaving with an intention not to reclaim or
      resume; an utter forsaking abandonment.

            Cession or dereliction, actual or tacit, of other
            powers.                               --Burke.

   2. A neglect or omission as if by willful abandonment.

            A total dereliction of military duties. --Sir W.
                                                  Scott.

   3. The state of being left or abandoned.

   4. (Law) A retiring of the sea, occasioning a change of
      high-water mark, whereby land is gained.

Source : WordNet®

dereliction
     n 1: a tendency to be negligent and uncaring; "he inherited his
          delinquency from his father"; "his derelictions were not
          really intended as crimes"; "his adolescent protest
          consisted of willful neglect of all his
          responsibilities" [syn: {delinquency}, {willful neglect}]
     2: willful negligence