Source : Webster's Revised Unabridged Dictionary (1913)

Negligence \Neg"li*gence\, n. [F. n['e]gligence, L.
   negligentia.]
   The quality or state of being negligent; lack of due
   diligence or care; omission of duty; habitual neglect;
   heedlessness.

   2. An act or instance of negligence or carelessness.

            remarking his beauties, . . . I must also point out
            his negligences and defects.          --Blair.

   3. (Law) The omission of the care usual under the
      circumstances, being convertible with the Roman culpa. A
      specialist is bound to higher skill and diligence in his
      specialty than one who is not a specialist, and liability
      for negligence varies acordingly.

   {Contributory negligence}. See under {Contributory}.

   Syn: Neglect; inattention; heedlessness; disregard; slight.

   Usage: {Negligence}, {Neglect}. These two words are freely
          interchanged in our older writers; but a distinction
          has gradually sprung up between them. As now generally
          used, negligence is the habit, and neglect the act, of
          leaving things undone or unattended to. We are
          negligent as a general trait of character; we are
          guilty of neglect in particular cases, or in reference
          to individuals who had a right to our attentions.

Source : WordNet®

negligence
     n 1: failure to act with the prudence that a reasonable person
          would exercise under the same circumstances [syn: {carelessness},
           {neglect}, {nonperformance}]
     2: the trait of neglecting responsibilities and lacking concern
        [syn: {neglect}, {neglectfulness}]