Noah Webster
Malignancy
MALIG'NANCY, noun [See Malignant.] Extreme malevolence; bitter enmity; malice; as malignancy of heart.
1. Unfavorableness; unpropitiousness; as the malignancy of the aspect of planets.
The malignancy of my fate might distemper yours.
2. Virulence; tendency to mortification or to a fatal issue; as the malignancy of an ulcer or of a fever.