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Synonyms

deadly

American  
[ded-lee] / ˈdɛd li /

adjective

deadlier, deadliest
  1. causing or tending to cause death; fatal; lethal.

    a deadly poison.

  2. aiming to kill or destroy; implacable.

    a deadly enemy.

  3. like death.

    a deadly pallor.

  4. excruciatingly boring.

    The dinner party was absolutely deadly.

    Synonyms:
    dreary, tedious, dull
  5. excessive; inordinate.

    deadly haste.

  6. extremely accurate.

    Annie Oakley was a deadly shot.


adverb

  1. in a manner resembling or suggesting death.

    deadly pale.

  2. excessively; completely.

    deadly dull.

deadly British  
/ ˈdɛdlɪ /

adjective

  1. likely to cause death

    deadly poison

    deadly combat

  2. informal extremely boring

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

adverb

  1. like death in appearance or certainty

    deadly pale

    a deadly sleep

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Related Words

See fatal.

Other Word Forms

  • deadliness noun
  • nondeadly adjective

Etymology

Origin of deadly

First recorded before 900; Middle English deedli(ch), Old English dēadlīce; dead, -ly

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Thailand has released 18 Cambodian soldiers that were captured in July during deadly border clashes as part of a ceasefire the two countries agreed to on Saturday.

From BBC

Thailand on Wednesday released 18 Cambodian soldiers captured in July, both governments said, after a fresh ceasefire between the neighbours held for more than three days following weeks of deadly border clashes.

From Barron's

Thailand on Wednesday released 18 Cambodian soldiers captured in July, both governments said, after a fresh ceasefire between the neighbours held for more than three days following weeks of deadly border clashes.

From Barron's

Lucas Paqueta was deadly with the chance to restore West Ham's lead, but Joel Veltman bundled in from a corner on the hour mark.

From Barron's

It’s also one of the deadliest peaks in the United States, in part due to its accessibility from such a large city.

From Los Angeles Times