deadly

adjective
dead·​ly | \ ˈded-lē How to pronounce deadly (audio) \
deadlier; deadliest

Definition of deadly

 (Entry 1 of 2)

1 : likely to cause or capable of producing death deadly poison
2a : aiming to kill or destroy : implacable a deadly enemy
b : highly effective a deadly exposé
c : unerring a deadly marksman
d : marked by determination or extreme seriousness
3a : tending to deprive of force or vitality a deadly habit
b : suggestive of death especially in dullness or lack of animation deadly bores a deadly conversation
4 : very great : extreme

deadly

adverb

Definition of deadly (Entry 2 of 2)

1 archaic : in a manner to cause death : mortally
2 : suggesting death
3 : extremely deadly serious

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Other Words from deadly

Adjective

deadliness noun

Choose the Right Synonym for deadly

Adjective

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

Adjective

deadly, mortal, and fatal mean causing or capable of causing death. deadly is used of something that is certain or very likely to cause death. The mushroom contains a deadly poison. mortal is used of something that already has caused death or is about to cause death. He received a mortal wound in battle. fatal is used when death is certain to follow. The wounds proved to be fatal.

Examples of deadly in a Sentence

Adjective

the world's most deadly snake a more deadly form of the disease They launched a deadly attack. Officers are allowed to use deadly force if necessary. She shoots with deadly accuracy. a basketball player with deadly aim A deadly silence followed his question. The two gang leaders are deadly enemies. He spoke with deadly seriousness.

Adverb

I'm deadly serious about making an offer on the house.
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Recent Examples on the Web: Adjective

Last year was the deadliest yet for civilians since the U.N. began keeping a record a decade ago, with almost 4,000 civilians killed and more than 7,000 injured. Los Angeles Times, "No deal yet with the Taliban, but Trump is planning big cuts in U.S. presence," 14 Aug. 2019 The Congo is experiencing the second-deadliest Ebola outbreak ever, with 1,800 succumbing to the virus since last summer. Aj Willingham, CNN, "5 things to know for August 13: Immigration, Dayton, Epstein, Ebola, Russia," 13 Aug. 2019 As his job went on, the tally got worse: 2018 was the deadliest for natural disasters in over a decade, with more than 4,600 people killed. The Economist, "Obituary: Sutopo Purwo Nugroho died on July 7th," 10 Aug. 2019 The El Paso store shooting, however, was the deadliest in the company's history, Walmart spokesman Randy Hargrove confirmed. Anne D'innocenzio, chicagotribune.com, "Days after El Paso shooting, Walmart is faced with how to make their workers and customers feel safe," 6 Aug. 2019 The El Paso shooting is one of the deadliest in US history. Morgan Lee, BostonGlobe.com, "El Paso absorbs more grief as death toll climbs to 22," 5 Aug. 2019 The El Paso shooting is one of the deadliest in U.S. history, and the death toll rose Monday as doctors announced that two more of the wounded had died. Author: Cedar Attanasio, Paul J. Weber, Morgan Lee, Anchorage Daily News, "El Paso absorbs more grief as shooting deaths climb to 22," 5 Aug. 2019 The El Paso shooting was the deadliest since Parkland, according to the data. Aric Chokey, sun-sentinel.com, "MAP: 17 died in Parkland, and then the U.S. saw 566 more mass shootings," 5 Aug. 2019 The El Paso is the deadliest since the November 2017 Sutherland Springs, Texas church shooting. Alejandro De La Garza, Time, "61 People Have Been Killed in Mass Shootings in 2019 Alone," 5 Aug. 2019

Recent Examples on the Web: Adverb

Sheffield United will be lifted by the crowd on their first home game, while Palace are deadly away from home and may have Wilfried Zaha back in the starting line-up. SI.com, "Sheffield United vs Crystal Palace Preview: Where to Watch, Buy Tickets, Live Stream & Team News," 14 Aug. 2019 The heat has the potential to break records and turn deadly as temperatures climb over the weekend all along the East Coast and through the Midwest. Cnn.com Wire Service, The Mercury News, "More than 185 million U.S. residents are under watches and warnings as dangerous heat wave begins," 19 July 2019 From the scorching Sonoran Desert to the fast-moving Rio Grande, the 2,000-mile U.S.-Mexico border has long been an at times deadly crossing between ports of entry. Peter Orsi, The Denver Post, "A grim father, daughter border drowning underlines peril facing many migrants," 26 June 2019 From the scorching Sonoran Desert to the fast-moving Rio Grande, the 2,000-mile U.S.-Mexico border has long been an at times deadly crossing between ports of entry. Washington Post, "Father-daughter border drowning highlights migrants’ perils," 26 June 2019 From the scorching Sonoran Desert to the fast-moving Rio Grande, the 2,000-mile U.S.-Mexico border has long been an at times deadly crossing between ports of entry. Peter Orsi And Amy Guthrie, chicagotribune.com, "A grim border drowning underlines peril facing many migrants," 26 June 2019 From the scorching Sonoran Desert to the fast-moving Rio Grande, the 2,000-mile U.S.-Mexico border has long been an at times deadly crossing between ports of entry. Author: Peter Orsi, Amy Guthrie, Anchorage Daily News, "Drowning of migrant father and daughter in Rio Grande highlights migrants’ perils," 25 June 2019 If Bourbon virus were to establish itself there in humans too, the chances go up that more cases, like Wilson’s, will turn deadly. Megan Molteni, WIRED, "The Meat-Allergy Tick Also Carries a Mystery Killer Virus," 8 July 2019 All too often, these types of incidents can turn deadly. Kim Chatelain, nola.com, "Road rage in Slidell leads to shooting: police," 27 June 2019

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

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First Known Use of deadly

Adjective

before the 12th century, in the meaning defined at sense 1

Adverb

before the 12th century, in the meaning defined at sense 1

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Statistics for deadly

Last Updated

18 Aug 2019

Look-up Popularity

Time Traveler for deadly

The first known use of deadly was before the 12th century

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More Definitions for deadly

deadly

adjective

English Language Learners Definition of deadly

 (Entry 1 of 2)

: causing or able to cause death
: extremely accurate and effective
: extreme or complete

deadly

adverb

English Language Learners Definition of deadly (Entry 2 of 2)

: extremely or completely

deadly

adjective
dead·​ly | \ ˈded-lē How to pronounce deadly (audio) \
deadlier; deadliest

Kids Definition of deadly

 (Entry 1 of 2)

1 : causing or capable of causing death deadly poisons
2 : meaning or hoping to kill or destroy deadly enemies
3 : very accurate He shot the arrow with deadly aim.

deadly

adverb

Kids Definition of deadly (Entry 2 of 2)

1 : in a way suggestive of death Her face was deadly pale.
2 : to an extreme degree deadly dull

deadly

adjective
dead·​ly | \ ˈded-lē How to pronounce deadly (audio) \
deadlier; deadliest

Medical Definition of deadly

: likely to cause or capable of causing death a deadly disease a deadly poison a deadly instrument

Other Words from deadly

deadliness \ -​nəs How to pronounce deadliness (audio) \ noun

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deadly

adjective
dead·​ly
deadlier; deadliest

Legal Definition of deadly

: likely to cause or capable of causing death also : dangerous sense 2

Note: Deadly and dangerous are sometimes used interchangeably, especially in connection with weapons or instruments.

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More from Merriam-Webster on deadly

Rhyming Dictionary: Words that rhyme with deadly

Thesaurus: All synonyms and antonyms for deadly

Spanish Central: Translation of deadly

Nglish: Translation of deadly for Spanish Speakers

Britannica English: Translation of deadly for Arabic Speakers

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