Synonyms for Denigration (same or very similar meaning)
WordNet sense 1 (a belittling comment):
belittlingWordNet sense 2 (an abusive attack on a person's character or good name):
aspersion, calumny, defamation, slanderWordNet sense 3 (the act of expressing disapproval (especially of yourself)):
deprecationFrom the ODE community, based on WordNetadd/edit