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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
Pakistan has experienced a series of deadly floods through the summer monsoon season, but a fresh deluge of heavy rain in early September intensified the humanitarian crisis. Shannon K. Kingston, ABC News, 9 Sep. 2025 The American administration has parked warships in the Caribbean Sea in a bid to tackle drug trafficking, culminating in a deadly attack on a Venezuelan vessel last week. Kate Nishimura, Sourcing Journal, 9 Sep. 2025
Adverb
While the tropical cyclone isn’t expected to hit the city, it is expected to bring rough seas and deadly rip currents to New York and New Jersey shorelines. Thomas Tracy, New York Daily News, 21 Aug. 2025 Florida’s worst impacts — deadly rip currents, rough boat conditions and high waves that surfers are excited about — are in effect through at least Friday. Alex Harris, Miami Herald, 20 Aug. 2025 See All Example Sentences for deadly
Recent Examples of Synonyms for deadly
Adjective
  • This mix of impulsivity and ambivalence highlights why a safe environment – without access to firearms or other lethal methods – can be the difference between life and death for someone in crisis.
    Emmy Betz, The Conversation, 5 Sep. 2025
  • Executions are on hold in Idaho as the state prison system remodels its execution chamber in the transition from lethal injection to a firing squad as the lead method.
    Kevin Fixler September 5, Idaho Statesman, 5 Sep. 2025
Adjective
  • Maple and Francesca each opted for dresses, with the former donning a semi-sheer black number and the latter choosing a silky brown slip dress matching her father's color palette.
    Anna Kaufman, USA Today, 10 Sep. 2025
  • This trend includes smaller, high-end homes and with buyers favoring places that offer meaningful features over sheer size or clout.
    Sheryl Estrada, Fortune, 9 Sep. 2025
Adjective
  • Bautista is already on the roll call as The Kurgen, the movie’s top villain, while Gillan is MacLeod’s Scottish and very mortal wife.
    Borys Kit, HollywoodReporter, 5 Sep. 2025
  • During the events of the season 1 finale, Justin's mortal sons Roman and Milo gained wizard powers.
    Sydney Bucksbaum, Entertainment Weekly, 4 Sep. 2025
Adverb
  • In extremely dense fog where visibility is near zero, the best course of action is to first turn on your hazard lights, then simply pull into a safe location such as a parking lot of a local business, and stop.
    KANSAS CITY STAR WEATHER BOT, Kansas City Star, 6 Sep. 2025
  • Lisa, 28, wore a black maxi dress with cutouts, and paired the look with an extremely rare Hermès Birkin while in South Korea's capital city.
    Madison E. Goldberg, PEOPLE, 5 Sep. 2025
Adjective
  • Researchers measured violent and property crime data from 2023, fatal car accidents, drug overdose deaths and excessive drinking rates.
    Tiffani Jackson, Fort Worth Star-Telegram, 4 Sep. 2025
  • Here’s what to know about the fatal crash.
    Miranda Jeyaretnam, Time, 4 Sep. 2025
Adjective
  • Khusnullin has earned Putin’s unconditional trust due to his lengthy experience in remaking cities.
    Yegor Mostovshikov, The Dial, 9 Sep. 2025
  • Hamas, however, said any talks would not be unconditional—underscoring the entrenchment on both sides.
    Amira El-Fekki‎, MSNBC Newsweek, 8 Sep. 2025
Adjective
  • This would not be the first NFL opening weekend to stare fans dead in the eye and lie to them.
    Mike Sando, New York Times, 8 Sep. 2025
  • For instance, Captain John Boats out of Plymouth during a whale watch last August came across a dead basking shark that was being scavenged by five to six blue sharks.
    Rick Sobey, Boston Herald, 7 Sep. 2025
Adverb
  • Because hot & sour soup is incredibly nuanced.
    Shindy Chen, Charlotte Observer, 5 Sep. 2025
  • In her new YouTube video, Katelynn explained how grief and depression have made daily tasks incredibly difficult for her, and a recent change in routine has further increased her poor mental state.
    Zoey Lyttle, PEOPLE, 4 Sep. 2025

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Cite this Entry

“Deadly.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/deadly. Accessed 10 Sep. 2025.

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