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

Examples of malignant in a Sentence

a highly malignant form of cancer

a powerful and malignant influence

Recent Examples on the Web

These cells may have the potential to become malignant (cancerous) but are not yet considered cancer. —Corey Whelan, Verywell Health, 15 Aug. 2024

But this time the question never dissipates, haunting Miller’s slow-burn epic like a malignant, merciless spirit. —Bilge Ebiri, Vulture, 15 May 2024

When this happens with a malignant tumor, it’s known as cancer recurrence. —Laura Dorwart, Verywell Health, 29 July 2024

Paying Tribute to the Celebrities Who Have Died in 2024 Hadley first revealed in December 2023 that he was diagnosed with seminoma cancer —which is a malignant germ cell tumor that is typically found in the testicle, per the National Library of Medicine. —Charna Flam, Peoplemag, 22 June 2024

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

• malignant melanoma

Kids Definition

malignant

adjective

ma·​lig·​nant mə-ˈlig-nənt 

1

: evil in influence or effect : injurious

2

: malicious sense 1

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