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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
Saturday's incident comes just two months after an American Airlines plane collided with a U.S. Army Black Hawk helicopter above the Potomac River in a deadly crash that killed 67 people. Saman Shafiq, USA Today, 31 Mar. 2025 Friday’s quake was the deadliest natural disaster to hit the country in years and comes as Myanmar reels from a civil war that since 2021 has damaged communication networks, battered health infrastructure and left millions without adequate food and shelter. Brad Lendon and Alex Stambaugh, CNN Money, 30 Mar. 2025
Adverb
Climate woes are stacking up in the wake of such extreme heat, with widespread flooding killing thousands across Africa, deadly landslides burying villages in Asia, and drought in South America shrinking rivers. Reuters, NBC News, 23 Nov. 2024 Widespread malnutrition after a year of dwindling food supplies is another factor making this winter deadly. Ghada Abdulfattah, The Christian Science Monitor, 7 Jan. 2025 See All Example Sentences for deadly
Recent Examples of Synonyms for deadly
Adjective
  • When carboxyhemoglobin saturation exceeds 50%, it is considered lethal.
    CBS News, CBS News, 3 Apr. 2025
  • Astronauts on a mission to Mars lasting several years would be exposed to potentially lethal amounts of radiation, Pitts said.
    Joshua Rhett Miller, MSNBC Newsweek, 2 Apr. 2025
Adjective
  • But the sheer volume of options in our modern world—especially in digital spheres such as online shopping, streaming services and mobile applications—can overcome the satisfaction of making these choices.
    Uriel Maslansky, Forbes.com, 4 Apr. 2025
  • But sheer athleticism won’t turn him into a celebrity, and his demeanor doesn’t endear him to people—Majors plays Maddox as a sullen and tightly wound outcast whose environment shapes his isolation.
    Hannah Giorgis, The Atlantic, 4 Apr. 2025
Adjective
  • According to Greek mythology, Castor and Pollux were the maternal twin sons of Leda, the mortal queen of Sparta.
    Mike Lynch, Twin Cities, 6 Apr. 2025
  • The series finds an adult Justin Russo (Henrie) living a normal, mortal life with his wife (Mimi Gianopulos) and kids (Alkaio Thiele and Max Matenko) — until his sister Alex (guest star and EP Selena Gomez) brings a young wizard named Billie (Janice LeAnn Brown) to him for training.
    Rick Porter, HollywoodReporter, 31 Mar. 2025
Adverb
  • Even some of Trump’s allies, including Elon Musk and Bill Ackman, have recently warned that tariffs are bad policy that rely on extremely flawed logic.
    John Towfighi, David Goldman and Matt Egan, CNN Money, 8 Apr. 2025
  • The fashion house’s artisans began experimenting with the material—which is extremely lightweight, strong, and pliable—and eventually created handles out of them by gently bending the stalks with fire and then applying many coats of lacquer.
    Diana Budds, Architectural Digest, 8 Apr. 2025
Adjective
  • The ordeal ended with the fatal exchange of gunfire about 9:50 p.m., more than five hours after the first call to deputies.
    Darrell Smith, Sacbee.com, 31 Mar. 2025
  • That is known as meconium aspiration syndrome – a potentially fatal condition that occurs in 5% to 10% of births but is treatable if diagnosed in time.
    Khwaga Ghani, NPR, 31 Mar. 2025
Adjective
  • His primary goal is providing unconditional love, which research shows sets children up for success broadly defined.
    Omaid Homayun, Forbes.com, 31 Mar. 2025
  • Earlier this week, Trump signed a full and unconditional pardon for Devon Archer, a one-time business partner of Hunter Biden, former President Joe Biden’s son.
    Dan Mangan, CNBC, 28 Mar. 2025
Adjective
  • On the second day of the year, police responded to a call where a father and his son and daughter were found dead.
    Laura Bauer, Kansas City Star, 8 Apr. 2025
  • Matthew Terrell Collins Sr., 58, and Matthew Terrell Collins Jr., 29, were pronounced dead at the scene around 6:06 p.m.
    David Matthews, New York Daily News, 8 Apr. 2025
Adverb
  • More Pro Wrestling: Pro Wrestling Legend Bret Hart Reacts to Record-Breaking WWE Hall of Fame Induction While there's no doubt that these wrestlers are incredibly talented, there are plenty of other WWE Superstars who are more than capable of carrying on a main event match.
    Jason D. Greenblatt, MSNBC Newsweek, 2 Apr. 2025
  • Shilpa loves cake, so what better time to introduce her incredibly springy, tender, and flavorful Pistachio Bundt Cake recipe!
    Bon Appétit, Bon Appetit Magazine, 2 Apr. 2025

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Cite this Entry

“Deadly.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/deadly. Accessed 14 Apr. 2025.

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