le·​thal | \ ˈlē-thəl How to pronounce lethal (audio) \

Definition of lethal

 (Entry 1 of 2)

1a : 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



Definition of lethal (Entry 2 of 2)

1 : an abnormality of genetic origin causing the death of the organism possessing it

Other Words from lethal


lethality \ lē-​ˈtha-​lə-​tē How to pronounce lethal (audio) \ noun
lethally \ ˈlē-​thə-​lē How to pronounce lethal (audio) \ adverb

Synonyms & Antonyms for lethal

Synonyms: Adjective

Antonyms: Adjective

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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 By canceling a critical gas deal with Russia and overturning a longstanding policy of not sending lethal weapons into war zones, Mr. Scholz has seized the garment and transformed Germany’s role in the world. Thomas S. Kaplan And Bernard-henri Lévy, WSJ, 15 May 2022 In another indication of the shift in the political mood, the German Parliament agreed in April to provide lethal weapons and defense systems to Ukraine, overcoming Germans’ post-World War II reluctance to getting involved in armed conflicts. New York Times, 5 May 2022 Unlike the sophisticated drones that many militaries use, the drones are widely available at stores like Best Buy, easily modified and hacked to turn them into lethal weapons. Jeanine Santucci, USA TODAY, 30 Apr. 2022 Hungary is not allowing its territory to be used for the transit of lethal weapons to Ukraine. Washington Post, 3 Apr. 2022 But so far, efforts at the United Nations to enact a restriction on the development and sale of lethal autonomous weapons have foundered. Jeremy Kahn, Fortune, 29 Mar. 2022 Germany sent 500 Stingers as part of the European Union’s $500 million lethal weapons purchase to Ukraine—the first time the EU ever supplied weapons for a country at war. Derek Saul, Forbes, 17 Mar. 2022 While the Trump administration was the first willing to provide lethal weapons to Ukraine, the Obama administration did provide defense and military equipment. Tara Subramaniam, CNN, 16 Mar. 2022 The surest way for the Browns to make Mayfield dangerous again is to supply him with one of the most lethal weapons in the NFL. cleveland, 10 Mar. 2022 Recent Examples on the Web: Noun 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 See More

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'lethal.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of lethal


circa 1604, in the meaning defined at sense 1a


1917, in the meaning defined at sense 1

History and Etymology for lethal

Adjective and Noun

Latin letalis, lethalis, from letum death

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Time Traveler for lethal

Time Traveler

The first known use of lethal was circa 1604

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Dictionary Entries Near lethal

let go of


lethal gene

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Statistics for lethal

Last Updated

20 May 2022

Cite this Entry

“Lethal.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/lethal. Accessed 22 May. 2022.

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More Definitions for lethal


le·​thal | \ ˈlē-thəl How to pronounce lethal (audio) \

Medical Definition of lethal

 (Entry 1 of 2)

: of, relating to, or causing death a lethal injury also : capable of causing death lethal chemicals a lethal dose

Other Words from lethal

lethality \ lē-​ˈthal-​ət-​ē How to pronounce lethal (audio) \ noun, plural lethalities
lethally adverb



Medical Definition of lethal (Entry 2 of 2)

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

More from Merriam-Webster on lethal

Nglish: Translation of lethal for Spanish Speakers

Britannica English: Translation of lethal for Arabic Speakers


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