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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
While world leaders bicker over the prospects for peace, the deadliest conflict in Europe since World War Two is heating up fast: swarms of drones are being launched by both sides while Russia is advancing at key points along the front. Guy Faulconbridge, USA Today, 29 May 2025 The deadly shooting outside Washington, D.C.’s Capital Jewish Museum has added to an ongoing conversation about antisemitism after Hamas’ brutal Oct. 7 massacre. Rachel Wolf, FOXNews.com, 29 May 2025
Adverb
In Another Simple Favor, Emily is released from jail and invites Stephanie to attend her lavish Italian wedding, to deadly ends. Jen Juneau, People.com, 30 Apr. 2025 Rounding up immigrants and even American citizens, Trump may be deadly serious giving 40.1 million Canadians new USA passports. Dominic Patten, Deadline, 28 Apr. 2025 See All Example Sentences for deadly
Recent Examples of Synonyms for deadly
Adjective
  • Stephen Stanko’s attorneys told him that lethal injection would feel like drowning when a lethal dose of pentobarbital is injected into the inmate’s veins and there’s a rush of fluid into the lungs.
    Brie Stimson, FOXNews.com, 30 May 2025
  • However, in the days to come, zoo officials faced mounting criticism for not trying to tranquilize the 17-year-old Western lowland silverback before using lethal force.
    Jillian Frankel, People.com, 28 May 2025
Adjective
  • The sheer emotional momentum of being part of something—a sea of people unified by purpose—dissipates into the static of daily life.
    Adam Met, Time, 3 June 2025
  • Johnson paired the look with sheer black tights, giving the ensemble a unified tonal element overall.
    Julia Teti, Footwear News, 3 June 2025
Adjective
  • Ultimately, chaos seems to be the only certainty should Abbas shuffle off his mortal coil.
    Sean Durns, The Washington Examiner, 6 June 2025
  • Most of it doesn’t entail a mortal risk to a hundred and fifty people for the sake of a television comedy program.
    Gideon Lewis-Kraus, New Yorker, 25 May 2025
Adverb
  • Mills, a longtime associate of Fiona Apple, knows this territory well: the pointed self-analysis of an extremely sensitive person.
    Jenn Pelly, Time, 7 June 2025
  • City’s academy has been extremely productive in recent years, with Phil Foden the shining light, but Rico Lewis, James McAtee, Oscar Bobb and O’Reilly are all now established squad players.
    Jordan Campbell, New York Times, 7 June 2025
Adjective
  • In addition to the loss of wildlife, collisions are also fatal to humans.
    Reader Commentary, Baltimore Sun, 30 May 2025
  • Her father was charged A CT baby had fractures and injuries medical personnel say could have been fatal.
    Staff report, Hartford Courant, 30 May 2025
Adjective
  • Both Merz and Zelensky criticized the Kremlin’s effective rejection of an unconditional ceasefire proposed by the U.S., which Kyiv accepted.
    Stefanie Dazio, Los Angeles Times, 28 May 2025
  • Ukraine has agreed to an unconditional 30-day ceasefire, proposed by the U.S., but Putin rejected it.
    Jackie Northam, NPR, 26 May 2025
Adjective
  • Emergency responders performed life-saving measures before he was pronounced dead, Allard said.
    Staff report, Hartford Courant, 7 June 2025
  • Goins was pronounced dead in the backyard shortly after paramedics arrived, the Star-Telegram previously reported.
    Lillie Davidson, Fort Worth Star-Telegram, 6 June 2025
Adverb
  • Huang held on, and did so through incredibly difficult stretches that included him fighting to keep his job.
    John Tamny, Forbes.com, 1 June 2025
  • Digital search features on platforms like Google aggregate from all posts available, so when Fosgate’s tweets first got popular, the biggest and most available information about her was both transphobic and incredibly cruel.
    CT Jones, Rolling Stone, 31 May 2025

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Cite this Entry

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

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