Source : Webster's Revised Unabridged Dictionary (1913)

Denigration \Den`i*gra"tion\, n. [L. denigratio.]
   1. The act of making black. --Boyle.

   2. Fig.: A blackening; defamation.

            The vigorous denigration of science.  --Morley.

Source : WordNet®

denigration
     n 1: a belittling comment [syn: {belittling}]
     2: an abusive attack on a person's character or good name [syn:
         {aspersion}, {calumny}, {slander}, {defamation}]
     3: the act of expressing disapproval (especially of yourself)
        [syn: {deprecation}]