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Definition of deadlynext
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deadly

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adverb

Synonym Chooser

How does the adjective deadly differ from other similar words?

Some common synonyms of deadly are fatal, lethal, and mortal. While all these words mean "causing or capable of causing death," deadly applies to an established or very likely cause of death.

a deadly disease

When would fatal be a good substitute for deadly?

In some situations, the words fatal and deadly are roughly equivalent. However, fatal stresses the inevitability of what has in fact resulted in death or destruction.

fatal consequences

When is lethal a more appropriate choice than deadly?

While in some cases nearly identical to deadly, lethal applies to something that is bound to cause death or exists for the destruction of life.

lethal gas

When could mortal be used to replace deadly?

The synonyms mortal and deadly are sometimes interchangeable, but mortal implies that death has occurred or is inevitable.

a mortal wound

Example Sentences

Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Recent Examples of deadly
Adjective
One year after deadly wildfires reshaped the region and tested the resilience of entire communities, Los Angeles gathered not in mourning, but in unity. Michelle Edgar, Daily News, 27 Jan. 2026 Hundreds of people marched peacefully through Center City Philadelphia Monday, rallying in solidarity with Minnesota and raising concerns about federal immigration enforcement and recent deadly encounters involving federal agents in Minneapolis. Eva Andersen, CBS News, 27 Jan. 2026
Adverb
People protesting deteriorating economic conditions in Iran took to the streets across several of the country’s provinces over the past day, with some demonstrations turning deadly after clashes with police. Mostafa Salem, CNN Money, 1 Jan. 2026 Details of how the incident turned deadly later in the night have not been released. Mark Price, Charlotte Observer, 21 Dec. 2025 See All Example Sentences for deadly
Recent Examples of Synonyms for deadly
Adjective
  • Thompson’s original death sentence was later overturned, but a jury again sentenced him to die by lethal injection following a new punishment trial in November 2005.
    Michael Sinkewicz, FOXNews.com, 29 Jan. 2026
  • Thompson, 55, was scheduled to receive a lethal injection Wednesday evening at the state penitentiary in Huntsville.
    CBS News, CBS News, 28 Jan. 2026
Adjective
  • El Capitan is a roughly 3,000-foot sheer granite wall — more than twice the height of the Empire State Building — in the northern valley of Yosemite National Park in California.
    Melissa Gaffney, CBS News, 25 Jan. 2026
  • The sheer size and scope of the site presented a range of logistical challenges ahead of the reopening.
    Shomik Mukherjee, Mercury News, 24 Jan. 2026
Adjective
  • Crowe will portray a swordsman who mentors Cavill's Highlander, and Bautista will play an antagonistic immortal known as the Kurgen, while Gillan will star as Connor's very mortal wife.
    Mekishana Pierre, Entertainment Weekly, 28 Jan. 2026
  • Belichick’s and Brady’s greatness and championships did not depend on Spygate, the coach already has paid his punishment for that, and the shrine in Canton, Ohio, is not restricted to mortal deities.
    Miami Herald, Miami Herald, 28 Jan. 2026
Adverb
  • Where these winds coincide with heavy snow, blizzard conditions are possible, with near-zero visibility and extremely dangerous travel, particularly along the Outer Banks of North Carolina and into southeast Virginia.
    Briana Waxman, CNN Money, 30 Jan. 2026
  • Therefore, telling the story in graphic form on behalf of Ukrainians themselves, explaining the preconditions for Russia’s attempts to erase Ukraine as a sovereign country and Ukrainians as an ethnic group, became extremely relevant.
    Literary Hub, Literary Hub, 29 Jan. 2026
Adjective
  • The fatal shooting of Renee Good by an Immigration and Customs Enforcement officer earlier this month proved to Carlson and other Minnesotans that the potential for danger as an observer was not abstract.
    Michael Williams, CNN Money, 28 Jan. 2026
  • Noem has been under increasing scrutiny following Saturday’s fatal shooting of 37-year-old Alex Pretti by federal authorities in Minneapolis.
    Christopher Cann, USA Today, 28 Jan. 2026
Adjective
  • Validation, on the other hand, is unconditional.
    Julie Kratz, Forbes.com, 25 Jan. 2026
  • According to Rhode Island General Laws, Section 6-13-10, this merchandise can be considered an unconditional gift without any obligation on the recipient's part to the sender.
    Bailey Allen, The Providence Journal, 16 Jan. 2026
Adjective
  • Medics immediately delivered aid, but Pretti was pronounced dead at the site of the shooting.
    Jackson Thompson, FOXNews.com, 25 Jan. 2026
  • Medics immediately tried to deliver medical aid to the subject, McLaughlin said, but he was pronounced dead on scene.
    Natalie Neysa Alund, USA Today, 25 Jan. 2026
Adverb
  • San Dieguito’s Director of Teaching Learning and Education Brieahna Weatherford said getting to this point has been incredibly challenging, the culmination of two years of work.
    Karen Billing, San Diego Union-Tribune, 27 Jan. 2026
  • At liftoff, there’s this incredibly gorgeous orange glow that came out of the bottom of the launch pad.
    Miami Herald Archives, Miami Herald, 27 Jan. 2026

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Cite this Entry

“Deadly.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/deadly. Accessed 31 Jan. 2026.

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