MALIG'NITY, n. [L. malignitas.] Extreme enmity, or evil dispositions of heart towards another; malice without provocation, or malevolence with baseness of heart; deep rooted spite.1. Virulence; destructive tendency; as the malignity of an ulcer or disease.2. Extreme evilness of nature; as the malignity of fraud.3. Extreme sinfulness; enormity or heinousness; as the malignity of sin.