Source : Webster's Revised Unabridged Dictionary (1913)

Symptom \Symp"tom\, n. [F. sympt[^o]me, Gr. ? anything that has
   befallen one, a chance, causality, symptom, fr. ? to fall
   together; sy`n with + ? to fall; akin to Skr. pat to fly, to
   fall. See {Syn-}, and cf. {Asymptote}, {Feather}.]
   1. (Med.) Any affection which accompanies disease; a
      perceptible change in the body or its functions, which
      indicates disease, or the kind or phases of disease; as,
      the causes of disease often lie beyond our sight, but we
      learn their nature by the symptoms exhibited.

            Like the sick man, we are expiring with all sorts of
            good symptoms.                        --Swift.

   2. A sign or token; that which indicates the existence of
      something else; as, corruption in elections is a symptom
      of the decay of public virtue.

   Syn: Mark; note; sign; token; indication.

Source : WordNet®

symptom
     n 1: (medicine) any sensation or change in bodily function that
          is experienced by a patient and is associated with a
          particular disease
     2: anything that accompanies X and is regarded as an indication
        of X's existence