·noun Unfavorableness; evil nature.
II. Malignancy ·noun The state of being a malignant.
III. Malignancy ·noun Virulence; tendency to a fatal issue; as, the malignancy of an ulcer or of a fever.
IV. Malignancy ·noun The state or quality of being malignant; extreme malevolence; bitter enmity; malice; as, malignancy of heart.