Definitions
1.Verbpresent participle and gerund of blacken
2.NounThe act or process of turning (becoming) black in colour.
3.NounThe result or an instance of such an act or process; a black stain or mark.
4.NounAny of various (dark-colored) surface treatments for metal substrates, to inhibit corrosion.
5.NounThe act of defaming or sullying."blackenings of my reputation"