The Collaborative International Dictionary of English v.0.48:

Vulgarization \Vul`gar*i*za"tion\, n.
   The act or process of making vulgar, or common.
   [1913 Webster]

WordNet (r) 3.0 (2006):

vulgarization
    n 1: the act of rendering something coarse and unrefined [syn:
         vulgarization, vulgarisation]
    2: the act of making something attractive to the general public
       [syn: popularization, popularisation, vulgarization,
       vulgarisation]