A malignant tumor or growth that is cancerous and potentially life-threatening. The scan revealed a malignant that had spread to the lymph nodes.
A person who is malevolent or wishes harm to others. (archaic) The reformers were opposed by the king's malignants.
A supporter of King Charles I during the English Civil War (usually capitalized, historical). Parliamentary troops seized the weapons held by the Malignants in the town.