MALIG'NANT, adjective [Latin malignus, maligno, from malus, evil.]
1. Malicious; having extreme malevolence or enmity; as a malignant heart.
2. Unpropitious; exerting pernicious influence; as malignant start.
3. Virulent; as a malignant ulcer.
4. Dangerous to life; as a malignant fever.
5. Extremely heinous; as the malignant nature of sin.
MALIG'NANT, noun A man of extreme enmity or evil intentions. [Not used.]