malignant

[ muh-lig-nuhnt ]

adjective

1. disposed to cause harm, suffering, or distress deliberately; feeling or showing ill will or hatred.

   Synonyms: malevolent, spiteful

   Antonyms: benign

2. very dangerous or harmful in influence or effect.

   Synonyms: pernicious, hurtful, perilous

   Antonyms: benign

3. Pathology.
   1. tending to produce death, as bubonic plague.
   2. (of a tumor) characterized by uncontrolled growth; cancerous, invasive, or metastatic.

   Antonyms: benign

malignant

/ məˈlɪɡnənt /

adjective

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

noun

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

malignant

/ mə-lĭg′nənt /

1. Tending to have a destructive clinical course, as a malignant illness.
2. Relating to cancer cells that are invasive and tend to metastasize. Malignant tumor cells are histologically more primitive than normal tissue.
3. Compare benign

malignant

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

Notes

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

Derived Forms

• maˈlignantly, adverb

Other Words From

• ma·lignant·ly adverb
• nonma·lignant adjective
• nonma·lignant·ly adverb
• semi·ma·lignant adjective
• semi·ma·lignant·ly adverb
• unma·lignant adjective
• unma·lignant·ly adverb

Word History and Origins

Origin of malignant¹

First recorded in 1535–45; from Late Latin malignant-, stem of malignāns, present participle of malignāre “to act maliciously”; malign, -ant

Word History and Origins

Origin of malignant¹

C16: from Late Latin malīgnāre to behave spitefully, from Latin malīgnus malign

Example Sentences

The cancers are often grouped together because they have many features in common and occur when malignant polyps develop in either of the digestive organs.

From Los Angeles Times

We can plainly see Trump’s narcissism and psychopathy grow more malignant as the film progresses.

From Los Angeles Times

And an ill-considered or malignant post can have lasting effect.

From Los Angeles Times

The mainstream news media’s failure to decipher Trumpism has repeatedly led them to normalize the wantonly corrupt ex-president’s extremely malignant behavior.

From Salon

Democrats’ bet is that Americans crave such relatability after a decade of Trump’s malignant narcissism and Joe Biden’s struggles with old age.

From Salon

Related Words

• cancerous
• deadly
• destructive
• fatal
• lethal
• mortal

Malignant Vs. Benign

What’s the difference between malignant and benign?

In a medical context, the word malignant is used to describe harmful masses or tumors that are cancerous and that grow and spread disease. The word benign is the opposite—it’s used to describe masses or tumors that are not cancerous (those that do not spread disease to other parts of the body).

Both words are sometimes also used in general ways. Malignant can mean harmful or intended or intending to cause harm, while benign can mean kind, favorable, or gracious.

The best clue to help remember their meanings is the prefix mal-, which means “bad” and shows up in a lot of other negative words, such as malfunction, malpractice, malicious, and maleficent.

Here’s an example of malignant and benign used correctly in the same sentence.

Example: She was afraid the lump was a malignant tumor, but it turned out to be a benign cyst—totally harmless.

Want to learn more? Read the full breakdown of the difference between malignant and benign.

Quiz yourself on malignant vs. benign!

Should malignant or benign be used in the following sentence?

I can assure you that my intentions are completely _____—I mean no harm.