The Collaborative International Dictionary of English v.0.48:

Vulgarity \Vul*gar"i*ty\, n. [Cf. F. vulgarit['e], L. vulgaritas
   the multitude.]
   [1913 Webster]
   1. The quality or state of being vulgar; mean condition of
      life; the state of the lower classes of society. --Sir T.
      Browne.
      [1913 Webster]

   2. Grossness or clownishness of manners of language; absence
      of refinement; coarseness.
      [1913 Webster]

            The reprobate vulgarity of the frequenters of
            Bartholomew Fair.                     --B. Jonson.
      [1913 Webster]

WordNet (r) 3.0 (2006):

vulgarity
    n 1: the quality of lacking taste and refinement [syn:
         coarseness, commonness, grossness, vulgarity,
         vulgarism, raunch]