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

In Western countries the rise in deadly infections has been primarily in hospitals. The Economist, "Attack of the superbugs: July 2041," 5 July 2019 Too many others in their communities making poor, fateful and, too often, deadly decisions. Roy S. Johnson | Rjohnson@al.com, al.com, "Johnson: The silent faith behind the decision not to prosecute Marshae Jones," 4 July 2019 Reporters with The Arizona Republic investigated the state's police shootings for 19 months and found that the deadly trend extends across Arizona. Maritza Dominguez, azcentral, "Gaggle podcast: What you need to know about police shootings across Arizona," 3 July 2019 An airstrike pulverized a migrant detention center in Libya early Wednesday, killing at least 44 people and wounding another 130 in one of the deadliest assaults on civilians since Libya plunged into chaos in 2011. Declan Walsh, New York Times, "Airstrike Kills Dozens of Migrants at Detention Center in Tripoli," 3 July 2019 Those efforts intensified after white nationalists gathered in the city in 2017 for a rally that descended into deadly violence. USA TODAY, "Kacey Musgraves, sneaker flap, skiing in July: News from around our 50 states," 3 July 2019 Deer farmers have been keen to learn as much as possible about resistance to CWD in hopes of breeding or selecting stock that could live longer in the face of the deadly disease. Paul A. Smith, Milwaukee Journal Sentinel, "Gov. Evers vetoes proposal to use hunters' fees to fund CWD research at deer farm," 3 July 2019 The deadly European heat wave of 2003 is a cautionary tale. Michele Cohen Marill, WIRED, "How Extreme Heat Overwhelms Your Body and Becomes Deadly," 3 July 2019 The new flaw is different from the one that doomed the deadly Lion Air and Ethiopian Airlines flights and killed 346 people. Sean O'kane, The Verge, "Boeing announces $100 million fund for families of 737 Max crash victims," 3 July 2019

Recent Examples on the Web: Adverb

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 This can turn deadly fast if heat waves strike and last for several days. Ivana Kottasová, CNN, "Europe prepares for scorching heat wave with public cooling rooms, mist showers and health warnings," 25 June 2019 While June has been particularly deadly, the first half of this year saw fewer homicides in the city than any year since 2012. Cameron Knight, Cincinnati.com, "June has been the deadliest month in Cincinnati since 2010," 13 June 2019 Other cases detail how similar callousness or poor judgment can turn deadly: In Knox County, Tennessee, an inmate who tried to kill himself with a razor six months earlier was given another one when readmitted on theft charges. Sharon Cohen, The Denver Post, "AP Investigation: Many U.S. jails fail to stop inmate suicides," 18 June 2019 Demonstrations on the Gaza-Israel border have picked up in the past two weeks, sometimes turning deadly as protesters have clashed with Israel’s security forces. Dov Lieber, WSJ, "Six Palestinians Die in Clashes at Gaza-Israel Border," 28 Sep. 2018 Schlenk used his next two picks with that in mind: Maryland’s Kevin Huerter (deadly from the outside) and Villanova forward Omari Spellman, who plays a creative offensive game and can hit the three-pointer. Bruce Jenkins, SFChronicle.com, "As the Warriors go their way, the big men multiply," 23 June 2018 OLYMPIA — Community advocates, law-enforcement groups and state lawmakers are vowing to quickly approve the compromise legislation that was thrown out by the courts earlier this year to change Washington’s police deadly-use-of-force law. Joseph O’sullivan, The Seattle Times, "Community advocates, law enforcement groups call for Legislature to pass compromise bill on police deadly force," 3 Dec. 2018 The economic consequences of peace were deadly, and the astronomic reparations Berlin was forced to pay continued to sabotage its economic recovery. Josef Joffe, WSJ, "Is Germany Slouching Toward Weimar Again?," 23 Sep. 2018

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

7 Jul 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

Comments on deadly

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