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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
In The Furious, when his daughter Rainy is abducted, humble tradesman Wang Wei is thrust into a deadly underworld of corruption and violence. Matt Grobar, Deadline, 28 Oct. 2025 California residents are still recovering after deadly wildfires swept through the Los Angeles area in January, so Dawes is working on a way to help out. Hannah Dailey, Billboard, 28 Oct. 2025
Adverb
The Milwaukee Brewers are deadly serious about their baseball this season. Don Riddell, CNN Money, 3 Oct. 2025 In 2010, an attempt by Israel to stop another flotilla turned deadly after navy commandos boarded one boat, killing at least nine passengers and wounding 30 more. New York Times, 1 Oct. 2025 See All Example Sentences for deadly
Recent Examples of Synonyms for deadly
Adjective
  • None of the agencies have claimed responsibility for using less-lethal weapons.
    Alex Brizee, Idaho Statesman, 24 Oct. 2025
  • But the lethal force has raised several legal questions, as past administrations have relied on law enforcement to interdict drug shipments.
    Alexandra Hutzler, ABC News, 24 Oct. 2025
Adjective
  • The sheer number of open Power 4 jobs is causing an issue for administrators, as there are only so many top names to fill these high-profile positions.
    Jordan Sigler, MSNBC Newsweek, 28 Oct. 2025
  • Styled by Molly Dickson, the simple yet formal footwear aligned with Sweeney’s spring 2026 Stella McCartney look, a form-fitting white minidress with sheer ruched fabric wrapped around a structured corset base with boning and exaggerated hips.
    Jaden Thompson, Footwear News, 28 Oct. 2025
Adjective
  • As both Hernández and Freeman asserted, Ohtani has quite the gap between him and a mortal man, but there are four more wins the Dodgers need to earn before the storybook season can be complete.
    Gabe Smallson, MSNBC Newsweek, 18 Oct. 2025
  • Dicker’s fifth and final field goal was straight and true despite a high snap on the winning kick against the Dolphins, a mortal lock if ever there was one.
    Elliott Teaford, Oc Register, 13 Oct. 2025
Adverb
  • Almeida is extremely likely to have wrestling success early in this fight, and the question becomes whether Volkov can survive and extend the matchup.
    Brett Appley, New York Times, 25 Oct. 2025
  • Last offseason, the Red Sox were extremely active, trading for ace pitcher Garrett Crochet and signing All-Star third baseman Alex Bregman.
    Shaun McAvoy, MSNBC Newsweek, 24 Oct. 2025
Adjective
  • Such a slow start proved fatal to Yeovil, who went on to finish bottom of the table after being made to wait until October 26 for their first Huish Park victory at the seventh attempt.
    Richard Sutcliffe, New York Times, 23 Oct. 2025
  • Shortly after being taken away by paramedics, the father of Owens' four children was informed over the phone that her injury proved fatal.
    Ryan Coleman, Entertainment Weekly, 22 Oct. 2025
Adjective
  • In a heartfelt tribute shared on Instagram, the princess thanked her mom for her unconditional support.
    Emily Weaver, PEOPLE, 17 Oct. 2025
  • Your love for the city, your team, and its players is unconditional.
    Aaron Portzline, New York Times, 17 Oct. 2025
Adjective
  • Mental health advocates said Lauren Spors' encounters with law enforcement in the days and hours before her mother was found dead show multiple points of possible intervention.
    David Clarey, jsonline.com, 27 Oct. 2025
  • Carrig and her newborn baby were pronounced dead at the scene, and Haile was taken to a local hospital to be treated for smoke inhalation, the DA said.
    Charlotte Phillipp, PEOPLE, 26 Oct. 2025
Adverb
  • Arguably the best thing about this season (other than every time Sage shows up on my TV screen) is how incredibly personal Savannah takes everything.
    Dalton Ross, Entertainment Weekly, 23 Oct. 2025
  • The country is incredibly violent.
    Fiction Non Fiction, Literary Hub, 23 Oct. 2025

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Cite this Entry

“Deadly.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/deadly. Accessed 29 Oct. 2025.

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