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
malignantly
adverb
as in villainously
in a mean or spiteful manner she's malignantly conspiring to ruin her rival's career Synonyms & Similar Words
Relevance
- villainously
- hatefully
- maliciously
- despitefully
- malevolently
- bitterly
- spitefully
- viciously
- virulently
- wickedly
- nastily
- hostilely
- venomously
- disagreeably
- cattily
- bitchily
- invidiously
- vindictively
- resentfully
- contemptuously
- disdainfully
- obnoxiously
- caustically
- antagonistically
- cruelly
- scornfully
- vituperatively
- balefully
- pitilessly
- ruthlessly
- unfeelingly
- meanly
- heartlessly
- mercilessly
- enviously
- callously
- unkindly
- jealously
- rancorously
- diabolically
- ungraciously
- acrimoniously
- inhumanely
- soullessly
- insensitively
- fiendishly
- felly
- ill
- deprecatingly
- envyingly
- caddishly
- evil-mindedly
- misanthropically
- kindlessly
- thoughtlessly
- inconsiderately
- hard-heartedly
- ill-naturedly
Antonyms & Near Antonyms
- benevolently
- benignantly
- kindly
- genially
- pleasantly
- agreeably
- affably
- amiably
- cordially
- graciously
- lovingly
- altruistically
- solicitously
- thoughtfully
- nicely
- sympathetically
- humanely
- mercifully
- considerately
- soulfully
- sensitively
- sweetly
- feelingly
- gently
- compassionately
- divinely
- good-humoredly
- good-naturedly
- tenderly
- kindheartedly
- angelically
- good-heartedly
- softheartedly