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

The system generates two scores, one for benign and one for malignant, each on a scale of zero to one. —Meredith Broussard, WIRED, 15 Mar. 2023

These isms have been busy raping the planet, based on an old, malignant story that the environment is nothing but dead stuff to exploit. —Hazlitt, 26 July 2023

Lozano’s visuals are consistently arresting, with terrific use of shadows to malignant effect. —David Rooney, The Hollywood Reporter, 19 July 2023

The lawsuit claims that in May 2011 Kim Chace was battling stage 4 glioblastoma — a highly malignant brain tumor. —Globe Staff, BostonGlobe.com, 11 July 2023

The La Jolla company hopes to complete development of a drug to fight malignant tumors by next year. —Merrie Monteagudo, San Diego Union-Tribune, 15 Mar. 2022

The doctors discovered fluid building up in Zen's head and a malignant tumor that required brain surgery. —Georgia Slater, PEOPLE.com, 7 Dec. 2021

The confluence of the pandemic and the disproportionate impact on people of color, the killings of George Floyd, Breonna Taylor and Ahmaud Arbery, among others, and the president’s malignant policy decisions and ignorant proclamations have laid the problem bare. —Otis R. Taylor Jr., SFChronicle.com, 2 Nov. 2020

Kitwood argued that care settings shaped by malignant social psychology can actually accelerate neurological decline. —Longreads, 14 Apr. 2020

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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

• 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