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
Further testing turned out that the tumor was malignant.
—
Chris Hays, The Orlando Sentinel, 29 May 2025
Phelan graduated high school in May 2024, and days before starting her freshman year of college, was diagnosed with an inoperable stage 4 malignant brain tumor, a GoFundMe for her states.
—Viola Flowers, NBC news, 26 May 2025
My son Jack was diagnosed in 2022 with retinoblastoma, a malignant childhood cancer of the central nervous system that originates and grows in the eye.
—Dayna Copeland, The Mercury News, 15 Mar. 2025
According to a GoFundMe page set up in her name, Phelan was eventually diagnosed with a grade 4 malignant brain tumor that was categorized as a glioma, a growth of cells that starts in the brain or spinal cord, according to the Mayo Clinic.
—Skyler Caruso, People.com, 26 May 2025
See All Example Sentences for malignant
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Chris Hays, The Orlando Sentinel, 29 May 2025
Phelan graduated high school in May 2024, and days before starting her freshman year of college, was diagnosed with an inoperable stage 4 malignant brain tumor, a GoFundMe for her states.
—Viola Flowers, NBC news, 26 May 2025
My son Jack was diagnosed in 2022 with retinoblastoma, a malignant childhood cancer of the central nervous system that originates and grows in the eye.
—Dayna Copeland, The Mercury News, 15 Mar. 2025
According to a GoFundMe page set up in her name, Phelan was eventually diagnosed with a grade 4 malignant brain tumor that was categorized as a glioma, a growth of cells that starts in the brain or spinal cord, according to the Mayo Clinic.
—Skyler Caruso, People.com, 26 May 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 17 Jun. 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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