Malignant

a. [ L. malignans, -antis, p. pr. of malignare, malignari, to do or make maliciously. See Malign, and cf. Benignant. ] 1. Disposed to do harm, inflict suffering, or cause distress; actuated by extreme malevolence or enmity; virulently inimical; bent on evil; malicious. [ 1913 Webster ]

A malignant and a turbaned Turk. Shak. [ 1913 Webster ]

2. Characterized or caused by evil intentions; pernicious. “Malignant care.” Macaulay. [ 1913 Webster ]

Some malignant power upon my life. Shak. [ 1913 Webster ]

Something deleterious and malignant as his touch. Hawthorne. [ 1913 Webster ]

3. (Med.) Tending to produce death; threatening a fatal issue; virulent; as, malignant diphtheria. [ 1913 Webster ]

Malignant pustule (Med.), a very contagious disease produced by infection of subcutaneous tissues with the bacterium Bacillus anthracis. It is transmitted to man from animals and is characterized by the formation, at the point of reception of the infection, of a vesicle or pustule which first enlarges and then breaks down into an unhealthy ulcer. It is marked by profound exhaustion and often fatal. The disease in animals is called charbon; in man it is called cutaneous anthrax, and formerly was sometimes called simply anthrax. [ 1913 Webster +PJC ]

n. (Med.) A chronic progressive anemia of older adults, thought to result from a lack of intrinsic factor (a substance secreted by the stomach that is responsible for the absorption of vitamin B-12); also called pernicious anemia. [ WordNet 1.5 ]

adv. In a malignant manner. [ 1913 Webster ]

n. (Med.), Any of several malignant neoplasms (usually of the skin) consisting of melanocytes; called also melanoma. It is classed as a type of skin cancer. [ WordNet 1.5 ]

n. (Med.), Same as malignancy{ 4 }.
Syn. -- malignancy, malignance, malignant tumor, metastatic tumor. [ WordNet 1.5 ]