malignant

play

adjective ma·lig·nant \ mə-ˈlig-nənt \

Definition of malignant

1 a obsolete :malcontent, disaffected

b :evil in nature, influence, or effect :injurious

a powerful and malignant influence

c :passionately and relentlessly malevolent :aggressively malicious

the malignant tongues of gossipers

2 :tending to produce death or deterioration

malignant malaria

; especially :tending to infiltrate, metastasize, and terminate fatally

a malignant tumor

—

malignantly

adverb

See malignant defined for English-language learners

See malignant defined for kids

Examples of malignant in a Sentence

a highly malignant form of cancer
a powerful and malignant influence

Recent Examples of malignant from the Web

McCain has been receiving treatment at the Mayo Clinic in Minnesota after doctors discovered a malignant brain tumor earlier this year.

— lindsay kimble, PEOPLE.com, "Sen. John McCain Celebrates His 81st Birthday Early with Wife Cindy and Daughter Meghan Amid Cancer Fight," 28 Aug. 2017
His mother was diagnosed with a malignant brain tumor in 2002.

— jr radcliffe, Milwaukee Journal Sentinel, "Kettle Moraine's Vince Tumbleson left job in San Francisco, came home to coach football in a place where he built emotional legacy," 23 Aug. 2017
Mike VI, who was 11 years old, was diagnosed in May of 2016 with spindle cell sarcoma, a malignant tumor derived from fibrous connective tissues of the bone.

— mark heim, AL.com, "Watch LSU's new mascot, Mike VII, make campus debut," 21 Aug. 2017
Glioblastoma is considered a grade IV tumor, the most malignant of gliomas.

— patricia zengerle, Alaska Dispatch News, "Sen. McCain diagnosed with aggressive brain cancer," 20 July 2017
Senator Ted Kennedy, who died in 2009 after being diagnosed with brain cancer one year prior, had a malignant glioma, a category which includes glioblastomas.

— Bloomberg.com, "Senator McCain Diagnosed With Brain Tumor After Clot Removed," 20 July 2017
Glioblastoma is considered a grade IV tumor, the most malignant of gliomas.

— patricia zengerle, Alaska Dispatch News, "Sen. McCain diagnosed with aggressive brain cancer," 20 July 2017
Glioblastoma makes up about half of all malignant (cancerous) brain tumors and affects around five people out of 100,000 per year.

— kate samuelson, Time, "John McCain Has Been Diagnosed With Glioblastoma. What Is That?," 20 July 2017
Glioblastoma is considered a grade IV tumor, the most malignant of gliomas.

— patricia zengerle, Alaska Dispatch News, "Sen. McCain diagnosed with aggressive brain cancer," 20 July 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'malignant.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Origin and Etymology of malignant

Late Latin malignant-, malignans, present participle of malignari

NEW! Time Traveler

First Known Use: 1542

See Words from the same year

malignant Synonyms

Synonyms

bad [slang], bitchy, catty, cruel, despiteful, malevolent, malicious, malign, hateful, mean, nasty, spiteful, vicious, virulent

Antonyms

benevolent, benign, benignant, loving, unmalicious

Near Antonyms

compassionate, good, good-hearted, kind, kindhearted, kindly, sympathetic, warm, warmhearted; affable, agreeable, amiable, cordial, friendly, genial, gracious, nice, pleasant; affectionate, amorous, sweet, tender, tenderhearted; humane; altruistic, high-minded, humanitarian, magnanimous, noble, philanthropic (also philanthropical)

MALIGNANT Defined for English Language Learners

malignant

play

adjective

Definition of malignant for English Language Learners

medical : very serious and dangerous : tending or likely to grow and spread in a rapid and uncontrolled way that can cause death
: very evil

MALIGNANT Defined for Kids

malignant

play

adjective ma·lig·nant \ mə-ˈlig-nənt \

Definition of malignant for Students

1 :malicious

2 :likely to cause death :deadly

—

malignantly

adverb

Medical Dictionary

malignant

play

adjective ma·lig·nant \ mə-ˈlig-nənt \

medical Definition of malignant

1 :tending to produce death or deterioration

malignant malaria

; especially :tending to infiltrate, metastasize, and terminate fatally

malignant tumors

— compare benign 1

2 :of unfavorable prognosis :not responding favorably to treatment

psychotic reactions with a malignant trend

Learn More about malignant

See words that rhyme with malignant Thesaurus: All synonyms and antonyms for malignant Spanish Central: Translation of malignant Nglish: Translation of malignant for Spanish speakers Britannica English: Translation of malignant for Arabic speakers

Seen and Heard

What made you want to look up malignant? Please tell us where you read or heard it (including the quote, if possible).

show

malignant

Definition of malignant

malignantly

Read the Latest from M-W

Examples of malignant in a Sentence

Recent Examples of malignant from the Web

Origin and Etymology of malignant

malignant Synonyms

Synonyms

Antonyms

Related Words

Near Antonyms

MALIGNANT Defined for English Language Learners

malignant

Definition of malignant for English Language Learners

MALIGNANT Defined for Kids

malignant

Definition of malignant for Students

malignantly

Medical Dictionary

malignant

medical Definition of malignant

Learn More about malignant

Seen and Heard

Love words? Need even more definitions?

Love words? Need even more definitions?

Words at Play

Ask the Editors

Word Games

Trending: Kim Jong Un: Trump a 'Dotard'

Let's Talk 'Tea'

These Are Fighting Words

Merriam-Webster's New Words Quiz—Fall 2017 Edition!

Words of the Year: 1066