denigrate

Etymology

From Latin dēnigrātus, the past participle of dēnigrāre (“to blacken”), from dē + nigrare (“to blacken”) (from niger (“black”)).

verb

1. (transitive) To criticise so as to besmirch; traduce, disparage or defame.
   Although in public Soviet officials tend to denigrate the French electric locomotives imported recently, there is little doubt that lessons learnt from these engines will be incorporated in new Russian designs. 1963 January, “Beyond the Channel: U.S.S.R.”, in Modern Railways, page 62
2. (transitive) To treat as worthless; belittle, degrade or disparage.
   You have no right to denigrate people and things that you have no personal experience with.
3. (rare) To blacken.