1.Disposed to do harm, inflict suffering, or cause distress; actuated by extreme malevolence or enmity; virulently inimical; bent on evil; malicious. "A malignant and a turbaned Turk."
2.Characterized or caused by evil intentions; pernicious. "Malignant care." "Some malignant power upon my life." "Something deleterious and malignant as his touch."
3.(Med.) Tending to produce death; threatening a fatal issue; virulent; as, malignant diphtheria.