Answer: blacken

AnswerCrossword Clue
BLACKENDouse the lights
BLACKENDefame
blackenDamage or destroy (someone's good reputation); defame
blackenBecome or make black or dark, esp. as a result of burning, decay, or bruising
blackento defame (to destroy the reputation of)
blacken(of the sky) Become dark as night or a storm approaches
blackenDye or color (the face or hair) black for camouflage or cosmetic effect