[ muh-lig-nuhnt ]
/ məˈlɪg nənt /


disposed to cause harm, suffering, or distress deliberately; feeling or showing ill will or hatred.
very dangerous or harmful in influence or effect.
  1. tending to produce death, as bubonic plague.
  2. (of a tumor) characterized by uncontrolled growth; cancerous, invasive, or metastatic.



We’ve gathered some interesting words donated to English from Portuguese … as well as some that just don’t translate at all. Do you know what they mean?
Question 1 of 11
Which of the following animal names traces its immediate origin to Portuguese?

Origin of malignant

1535–45; <Late Latin malignant- (stem of malignāns), present participle of malignāre to act maliciously. See malign, -ant

OTHER WORDS FROM malignant Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2021

Example sentences from the Web for malignant

British Dictionary definitions for malignant

/ (məˈlɪɡnənt) /


having or showing desire to harm others
tending to cause great harm; injurious
pathol (of a tumour) uncontrollable or resistant to therapy; rapidly spreading


history (in the English Civil War) a Parliamentarian term for a royalist (def. 1)

Derived forms of malignant

malignantly, adverb

Word Origin for malignant

C16: from Late Latin malīgnāre to behave spitefully, from Latin malīgnus malign
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Medical definitions for malignant

[ mə-lĭgnənt ]


Threatening to life, as a disease; virulent.
Tending to metastasize; cancerous. Used of a tumor.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Scientific definitions for malignant

[ mə-lĭgnənt ]

Tending to have a destructive clinical course, as a malignant illness.
Relating to cancer cells that are invasive and tend to metastasize. Malignant tumor cells are histologically more primitive than normal tissue. Compare benign.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Cultural definitions for malignant


A descriptive term for things or conditions that threaten life or well-being. Malignant is the opposite of benign.

notes for malignant

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

notes for malignant

The term is often used in a general way to denote something that is both destructive and fast growing: “The malignant growth of the suburbs is destroying the landscape.”
The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.