Synonyms & Antonyms of deadly

(Entry 1 of 2)

3 of, relating to, or suggestive of death
  • a deadly pallor spread across her face as the tragic news gradually sank in

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Synonyms & Antonyms of deadly (Entry 2 of 2)

to a great degree
  • I'm deadly serious about making an offer on the house

Synonyms for deadly

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Frequently Asked Questions About deadly

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

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Time Traveler for deadly

Time Traveler

The first known use of deadly was before the 12th century

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Thesaurus Entries Near deadly



dead metaphor

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Cite this Entry

“Deadly.” Thesaurus, Merriam-Webster, Accessed 28 May. 2022.

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More from Merriam-Webster on deadly

Nglish: Translation of deadly for Spanish Speakers

Britannica English: Translation of deadly for Arabic Speakers


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