from The American Heritage® Dictionary of the English Language, 4th Edition

  • adj. Showing great malevolence; disposed to do evil.
  • adj. Highly injurious; pernicious.
  • adj. Pathology Threatening to life; virulent: a malignant disease.
  • adj. Pathology Tending to metastasize; cancerous. Used of a tumor.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • adj. Harmful, malevolent, injurious.
  • adj. Harmfully cancerous; as a malignant tumor.

from the GNU version of the Collaborative International Dictionary of English

  • adj. Disposed to do harm, inflict suffering, or cause distress; actuated by extreme malevolence or enmity; virulently inimical; bent on evil; malicious.
  • adj. Characterized or caused by evil intentions; pernicious.
  • adj. Tending to produce death; threatening a fatal issue; virulent.
  • n. A man of extreme enmity or evil intentions.
  • n. One of the adherents of Charles I. or Charles II.; -- so called by the opposite party.

from The Century Dictionary and Cyclopedia

  • Disposed to inflict suffering or cause distress; having extreme malevolence or enmity; virulently hostile; malicious: as, a malignant heart.
  • Virulently harmful or mischievous; threatening great danger; pernicious in influence or effect.
  • Specifically
  • In astrology, threatening to fortune or life; fateful: as, the malignant aspect of the stars.
  • In pathology, virulent; tending; to produce death; threatening a fatal issue: as, a malignant ulcer; a malignant fever; malignant pustule or scarlet fever.
  • Extremely heinous: as, the malignant nature of sin.
  • Synonyms Malevolent, bitter, rancorous, spiteful, malign. See animosity.
  • n. A person of extreme enmity or evil intentions; an ill-affected person.
  • n. Specifically, in English history, one of the adherents of Charles I. and his son Charles II. during the civil war; a Royalist; a Cavalier: so called by the Roundheads, the opposite party.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • adj. dangerous to health; characterized by progressive and uncontrolled growth (especially of a tumor)


Sorry, no etymologies found.


  • _malignant_ and _poisonous_ affections, as scirrhus and other varieties of cancer, and also cases of infectious virus, demand continually, or with but occasional exceptions, the primary galvanic current A B. ☞ In treating these malignant affections, the current should be run through as short a distance of _healthy_ tissue as possible, yet so as fairly to reach the diseased part.

    A Newly Discovered System of Electrical Medication

  • ‡ The term malignant is used in describing cancerous tumors (see cancer) because such growths are a threat to the health of the individual.


  • Congressman Foley is the poster child for what we call malignant narcissism.

    CNN Transcript Oct 4, 2006

  • Sure, there was that initial rush of anxiety at hearing the word "malignant" for the first time, but it was already disappearing by the time I got off the phone with the surgeon. Top headlines

  • APL is characterized by the malignant proliferation of these immature promyelocytes.

    The Emperor of All Maladies

  • This trial was the first to report a survival advantage from chemotherapy in malignant pleural mesothelioma showing a statistically significant improvement in median survival from 10 months in the patients treated with cisplatin alone to 13.3 months in the combination pemetrexed group in patients who received supplementation with folate and vitamin B12.


  • We wish the name malignant were obsolete and antiquate, if so be the thing itself, which is such a root of bitterness, were extirpated out of the church.

    The Works of the Rev. Hugh Binning

  • However, they do nothing to block long-wave ultraviolet radiation which is the major cause of a skin cancer, known as malignant melanoma.

    Samuel S. Epstein: How to Sunbathe Safely

  • Apart from increased risks of sunburn, AHAs also increase risks of a dangerous skin cancer, known as malignant melanoma.

    Samuel S. Epstein: Anti-Aging and Anti-Wrinkling Skin Care Products: Cosmeceuticals

  • SANJAY GUPTA, CNN CHIEF MEDICAL CORRESPONDENT (voice-over): Senator Ted Kennedy learned his diagnosis in May 2008, a brain tumor called a malignant glioma.

    CNN Transcript Aug 26, 2009


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  • Good question! Sadly, almost no one uses malign these days. Such a great word....

    September 22, 2007

  • Why is the opposite of malignant "benign" and not "benignant"?

    September 21, 2007