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
a malignant tumor
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
Synonyms
- bad [slang]
- bitchy
- catty
- cruel
- despiteful
- hateful
- malevolent
- malicious
- malign
- mean
- nasty
- spiteful
- vicious
- virulent
See all Synonyms & Antonyms 
Example Sentences
a highly malignant form of cancer a powerful and malignant influence
Recent Examples on the Web Shortly after his birth, doctors discovered fluid building up inside the baby boy's head in addition to a malignant tumor that required brain surgery. 
PEOPLE.com, 23 June 2022 Rather than just using psychiatric labeling to call a leader a narcissist or a malignant narcissist, something like that, that's probably not as helpful. CBS News, 9 Mar. 2022 One who actively undermines the competition is malignant. WSJ, 2 Aug. 2022 Of these surgeries, between 13 to 21% of these cysts are considered to be malignant. Serena Coady, SELF, 25 Feb. 2022 Zen died at five months old in December from a malignant brain tumor. Anna Chan, Billboard, 15 July 2022 Multiple myeloma is a blood cancer that forms in the body’s bone marrow, displacing the healthy, infection-fighting white blood cells with malignant plasma cells, which may lead to bone problems, tumors, infections, kidney damage and anemia. Alison Cross, Hartford Courant, 8 July 2022 Melissa Ward was told the malignant tumor in her right breast had been successfully treated with chemotherapy and a subsequent double mastectomy in 2018. Darcy Costello, Baltimore Sun, 28 June 2022 Following a CAT scan and more tests, a biopsy of his liver discovered a malignant tumor that had spread to his colon. Kyle Neddenriep, The Indianapolis Star, 23 June 2022 See More
PEOPLE.com, 23 June 2022 Rather than just using psychiatric labeling to call a leader a narcissist or a malignant narcissist, something like that, that's probably not as helpful. CBS News, 9 Mar. 2022 One who actively undermines the competition is malignant. WSJ, 2 Aug. 2022 Of these surgeries, between 13 to 21% of these cysts are considered to be malignant. Serena Coady, SELF, 25 Feb. 2022 Zen died at five months old in December from a malignant brain tumor. Anna Chan, Billboard, 15 July 2022 Multiple myeloma is a blood cancer that forms in the body’s bone marrow, displacing the healthy, infection-fighting white blood cells with malignant plasma cells, which may lead to bone problems, tumors, infections, kidney damage and anemia. Alison Cross, Hartford Courant, 8 July 2022 Melissa Ward was told the malignant tumor in her right breast had been successfully treated with chemotherapy and a subsequent double mastectomy in 2018. Darcy Costello, Baltimore Sun, 28 June 2022 Following a CAT scan and more tests, a biopsy of his liver discovered a malignant tumor that had spread to his colon. Kyle Neddenriep, The Indianapolis Star, 23 June 2022 See More Word History
Etymology
Late Latin malignant-, malignans, present participle of malignari
First Known Use
1542, in the meaning defined at sense 2c
Phrases Containing malignant
Kids Definition
malignant
adjective
ma·lig·nant mə-ˈlig-nənt
1
: malicious
2
: likely to cause death : deadly
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
malignant
adjective
as in malicious
having or showing a desire to cause someone pain or suffering for the sheer enjoyment of it a malignant wish to lash out at everyone who was smarter, richer, or better-looking than he was Synonyms & Similar Words
Relevance
- malicious
- vicious
- cruel
- hateful
- malign
- malevolent
- nasty
- virulent
- despiteful
- spiteful
- bad
- venomous
- poisonous
- evil
- bitchy
- bitter
- jealous
- catty
- vindictive
- hostile
- obnoxious
- mean
- harsh
- scoundrelly
- baneful
- scurvy
- snakelike
- vitriolic
- devious
- baleful
- opprobrious
- resentful
- jaundiced
- envious
- unkind
- rancorous
- contemptuous
- acrimonious
- inimical
- snotty
- unkindly
- derogatory
- caustic
- deprecating
- scornful
- disdainful
- unloving
- disparaging
- snide
- mean-spirited
- acrid
- scathing
Antonyms & Near Antonyms
- benign
- benevolent
- benignant
- loving
- sympathetic
- good
- kind
- warm
- compassionate
- amiable
- friendly
- kindly
- kindhearted
- pleasant
- genial
- agreeable
- unmalicious
- gracious
- affable
- cordial
- sweet
- nice
- affectionate
- amorous
- warmhearted
- good-hearted
- humane
- tender
- noble
- altruistic
- philanthropic
- humanitarian
- magnanimous
- tenderhearted
- philanthropical
- high-minded