malignant
adjective
ma·lig·nant
mə-ˈlig-nənt 
1
: tending to produce death or deterioration
malignant malaria
2
a
: evil in nature, influence, or effect : injurious
a powerful and malignant influence
b
: passionately and relentlessly malevolent : aggressively malicious
the malignant tongues of gossipers
c
obsolete
: malcontent, disaffected
malignantly
adverb
Examples of malignant in a Sentence
a highly malignant form of cancer
a powerful and malignant influence
Recent Examples on the Web
The fundraiser follows McIvor’s announcement earlier this month that he’d been diagnosed with glioblastoma, the most common and aggressive type of malignant brain tumor experienced by adults.
—
Katie Bain, Billboard, 15 July 2025
The test measures the level of PSA, a protein produced by normal as well as malignant prostate gland cells, in the blood.
—Ronnie Cohen, NPR, 21 May 2025
Those who are diagnosed with the malignant tumor have a median survival rate of about 14 to 14.5 months.
—Vanessa Etienne, People.com, 23 July 2025
Oates presents the idea of malignant artistic inspiration.
—Heather Scott Partington, Los Angeles Times, 16 June 2025
See All Example Sentences for malignant
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Katie Bain, Billboard, 15 July 2025
The test measures the level of PSA, a protein produced by normal as well as malignant prostate gland cells, in the blood.
—Ronnie Cohen, NPR, 21 May 2025
Those who are diagnosed with the malignant tumor have a median survival rate of about 14 to 14.5 months.
—Vanessa Etienne, People.com, 23 July 2025
Oates presents the idea of malignant artistic inspiration.
—Heather Scott Partington, Los Angeles Times, 16 June 2025
See All Example Sentences for malignant
Cite this Entry
“Malignant.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/malignant. Accessed 20 Aug. 2025.
Copy CitationKids Definition
malignant
adjective
ma·lig·nant
mə-ˈlig-nənt
1
: evil in influence or effect : injurious
3
: tending to produce death
malignant tumors
malignantly
adverb
Medical Definition
malignant
adjective
ma·lig·nant
mə-ˈlig-nənt
1
: tending to produce death or deterioration
malignant malaria
especially
: tending to infiltrate, metastasize, and terminate fatally
malignant tumors
compare benign sense 1
2
: of unfavorable prognosis : not responding favorably to treatment
psychotic reactions with a malignant trend
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