to blacken (e.g. commando's face for camouflage); to smear sb's name; to discredit; to black out or obliterate (e.g. censored words); to bring shame upon (oneself or one's family etc); to defame
（动）涂抹黑色，常比喻丢脸或丑化。
涂抹黑色。比喻丑化。
柳青 《创业史》第一部第一章：“ 秀兰 可是我的骨血哇！是我把她订亲给 杨 家的。眼时我还活着哩！不许她给我老脸上抹黑！”