MALIG'NANT, a. [L. 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, n. A man of extreme enmity or evil intentions. [Not used.]