A black mark is an indication of a negative event or action, and can be used to refer to a variety of different things. CENSURE is a formal expression of disapproval, while BLEMISH is an imperfection that mars the appearance of something. DEMERIT is a fault or error that causes someone to be blamed or punished, and SMUT is a word for dirt or filth. STIGMA is a mark of disgrace associated with a particular circumstance, quality, or person, and BLOT is a spot or stain that discredits someone's reputation. Finally, DISCREDIT is the act of damaging someone's reputation or integrity.