blackening

verb

Present participle of blacken

noun

1. The act or process of turning (becoming) black in colour.

2. The result or an instance of such an act or process; a black stain or mark.

3. Any of various (dark-colored) surface treatments for metal substrates, to inhibit corrosion; on steel, generally, synonym of bluing.

4. The act of defaming or sullying.

   “blackenings of my reputation”

5. Changing to a darker color

   Similar: darkening