The Collaborative International Dictionary of English v.0.48:

Aura \Au"ra\, n.; pl. Aur[ae]. [L. aura air, akin to Gr. ?.]
   1. Any subtile, invisible emanation, effluvium, or exhalation
      from a substance, as the aroma of flowers, the odor of the
      blood, a supposed fertilizing emanation from the pollen of
      flowers, etc.
      [1913 Webster]

   2. (Med.) The peculiar sensation, as of a light vapor, or
      cold air, rising from the trunk or limbs towards the head,
      a premonitory symptom of epilepsy or hysterics.
      [1913 Webster]

   Electric aura, a supposed electric fluid, emanating from an
      electrified body, and forming a mass surrounding it,
      called the electric atmosphere. See Atmosphere, 2.
      [1913 Webster]