lethal

1 of 2

adjective

le·​thal ˈlē-thəl How to pronounce lethal (audio)
1
a
: of, relating to, or causing death
death by lethal injection
b
: capable of causing death
lethal chemicals
2
: gravely damaging or destructive : devastating
a lethal attack on his reputation
3
: very potent or effective
a lethal fastball
also : having a high alcohol content
a lethal rum punch
lethality noun
lethally adverb

lethal

2 of 2

noun

1
: an abnormality of genetic origin causing the death of the organism possessing it
2
Choose the Right Synonym for lethal

deadly, mortal, fatal, lethal mean causing or capable of causing death.

deadly applies to an established or very likely cause of death.

a deadly disease

mortal implies that death has occurred or is inevitable.

a mortal wound

fatal stresses the inevitability of what has in fact resulted in death or destruction.

fatal consequences

lethal applies to something that is bound to cause death or exists for the destruction of life.

lethal gas

Examples of lethal in a Sentence

Adjective a potentially lethal dose of a drug He was sentenced to death by lethal injection.
Recent Examples on the Web
Adjective
At that point, SWAT officers utilized less lethal launchers. Jen Guadarrama, The Indianapolis Star, 1 Apr. 2024 Ives admits to working with a private company on an autonomous lethal antitank drone for the good of national security. Sara Netzley, EW.com, 1 Apr. 2024 In Peacemaker, Holland’s character is a lethal operative who acts as the Peacemaker's handler in the field. Kaitlin Stevens, Peoplemag, 31 Mar. 2024 Surgeon General of the United States, Dr. Vivek Murthy, in his 2023 81-page report, declared loneliness a lethal pandemic, equating it to smoking 15 cigarettes a day. Julian Hayes Ii, Forbes, 30 Mar. 2024 These units are designed to be smaller, lighter, more mobile — and, their leaders argue, more lethal. Ellen Nakashima, Washington Post, 29 Mar. 2024 Twenty — or five times the lethal dose — is not accidental. CBS News, 27 Mar. 2024 The Missouri Supreme Court on Wednesday declined to halt the execution of Brian Dorsey, who is scheduled to die by lethal injection next month for killing his cousin and her husband 18 years ago. CBS News, 21 Mar. 2024 Georgia uses the sedative pentobarbital in lethal injections, according to the Death Penalty Information Center. Andrew Jeong, Washington Post, 21 Mar. 2024
Noun
There are already concerns in Australia about the rate of escalation of force at some protests and about the use of less-than-lethal weaponry itself. Kylie Bourne, Discover Magazine, 14 Sep. 2015 Almost 8 of 10 lethal overdose victims had no contact with the agency before their deaths, the report found. Washington Post, 4 Sep. 2020 In response to Russian operations and Chinese advances, the USAF is battling for air superiority in the Arctic with its most valuable—and lethal—assets in Alaska, including the F-22A Raptor and F-35A Joint Strike Fighter. Jeff Bolton, Popular Mechanics, 19 July 2020

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'lethal.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

Etymology

Adjective and Noun

Latin letalis, lethalis, from letum death

First Known Use

Adjective

circa 1604, in the meaning defined at sense 1a

Noun

1917, in the meaning defined at sense 1

Time Traveler
The first known use of lethal was circa 1604

Dictionary Entries Near lethal

Cite this Entry

“Lethal.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/lethal. Accessed 13 Apr. 2024.

Kids Definition

lethal

1 of 2 adjective
le·​thal ˈlē-thəl How to pronounce lethal (audio)
: causing or capable of causing death
lethal chemicals
lethally adverb

lethal

2 of 2 noun

Medical Definition

lethal

1 of 2 adjective
le·​thal ˈlē-thəl How to pronounce lethal (audio)
: of, relating to, or causing death
a lethal injury
also : capable of causing death
lethal chemicals
a lethal dose
lethality noun
plural lethalities
lethally adverb

lethal

2 of 2 noun
1
: an abnormality of genetic origin causing the death of the organism possessing it usually before maturity
2

More from Merriam-Webster on lethal

Last Updated: - Updated example sentences
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