denigrate
v.
1520s, from Latin denigratus, past participle of denigrare "to blacken, defame," from de- "completely" (see de-) + nigr-, stem of niger "black" (see Negro). which is of unknown origin. "Apparently disused in 18th c. and revived in 19th c." [OED]. Related: Denigrated; denigrating.
〔蒋〕[de-使成为…，nigr黑，-ate动词后缀] 使黑，抹黑，贬低，底毁