Source : Webster's Revised Unabridged Dictionary (1913)

Accident \Ac"ci*dent\, n. [F. accident, fr. L. accidens,
   -dentis, p. pr. of accidere to happen; ad + cadere to fall.
   See {Cadence}, {Case}.]
   1. Literally, a befalling; an event that takes place without
      one's foresight or expectation; an undesigned, sudden, and
      unexpected event; chance; contingency; often, an
      undesigned and unforeseen occurrence of an afflictive or
      unfortunate character; a casualty; a mishap; as, to die by
      an accident.

            Of moving accidents by flood and field. --Shak.

            Thou cam'st not to thy place by accident: It is the
            very place God meant for thee.        --Trench.

   2. (Gram.) A property attached to a word, but not essential
      to it, as gender, number, case.

   3. (Her.) A point or mark which may be retained or omitted in
      a coat of arms.

   4. (Log.)
      (a) A property or quality of a thing which is not
          essential to it, as whiteness in paper; an attribute.
      (b) A quality or attribute in distinction from the
          substance, as sweetness, softness.

   5. Any accidental property, fact, or relation; an accidental
      or nonessential; as, beauty is an accident.

            This accident, as I call it, of Athens being
            situated some miles from the sea.     --J. P.
                                                  Mahaffy.

   6. Unusual appearance or effect. [Obs.] --Chaucer.

   Note: Accident, in Law, is equivalent to casus, or such
         unforeseen, extraordinary, extraneous interference as
         is out of the range of ordinary calculation.

Source : WordNet®

accident
     n 1: a mishap; especially one causing injury or death
     2: anything that happens by chance without an apparent cause
        [syn: {fortuity}, {chance event}]