Source : Webster's Revised Unabridged Dictionary (1913)

Vertigo \Ver"ti*go\ (?; 277), n.; pl. E. {Vertigoes}, L.
   {Vertigines}. [L., fr. vertere to turn. See {Verse}.]
   1. (Med.) Dizziness or swimming of the head; an affection of
      the head in which objects, though stationary, appear to
      move in various directions, and the person affected finds
      it difficult to maintain an erect posture; giddiness.
      --Quian.

   2. (Zo["o]l.) Any one of numerous species of small land
      snails belonging to the genus {Vertigo}, having an
      elongated or conical spiral shell and usually teeth in the
      aperture.

Source : WordNet®

vertigo
     n : a reeling sensation; feeling about to fall [syn: {dizziness},
          {giddiness}, {lightheadedness}]
     [also: {vertigoes} (pl), {vertigines} (pl)]