1. the process of becoming black or making something black
2. a substance used to make something black

1. present participle of blacken; making or becoming black or dark

Examples

• The blackening of the sky warned of an approaching storm.
• She applied shoe blackening to restore the leather boots.
• The metal showed signs of blackening from the heat.
• Smoke was blackening the walls of the old building.
• The blackening process takes several hours to complete.
• His reputation suffered a gradual blackening over time.
• The chef specializes in blackening fish with spices.