DENIGRATING
calumniatory, calumnious, defamatory, denigrative, denigrating, denigratory, libellous, libelous, slanderous
(adjective) (used of statements) harmful and often untrue; tending to discredit or malign
Source: WordNet® 3.1
Verb
denigrating
present participle of denigrate
Source: Wiktionary
DENIGRATE
Den"i*grate, v. t. Etym: [L. denigrare; de- + nigrare to blacken,
niger black.]
1. To blacken thoroughly; to make very black. Boyle.
2. Fig.: To blacken or sully; to defame. [R.]
To denigrate the memory of Voltaire. Morley.
Source: Webster’s Unabridged Dictionary 1913 Edition