The Collaborative International Dictionary of English v.0.48:

Vulgarize \Vul"gar*ize\, v. t. & i. [imp. & p. p. Vulgarized;
   p. pr. & vb. n. Vulgarizing.] [Cf. F. vulgariser, LL.
   vulgarizare.]
   To make vulgar, or common.
   [1913 Webster]

         Exhortation vulgarized by low wit.       --V. Knox.
   [1913 Webster]