[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.