Wordnet 3.0
NOUN (1)
1. 
 a person who lowers the quality or character or value (as by adding cheaper metal to coins); 
[syn: debaser, degrader]
WordNet (r) 3.0 (2006):
degrader
    n 1: a person who lowers the quality or character or value (as
         by adding cheaper metal to coins) [syn: debaser,
         degrader]