9 Grammatical Pitfalls


[ded-lee] /ˈdɛd li/
adjective, deadlier, deadliest.
causing or tending to cause death; fatal; lethal:
a deadly poison.
aiming to kill or destroy; implacable:
a deadly enemy.
like death:
a deadly pallor.
excruciatingly boring:
The dinner party was absolutely deadly.
excessive; inordinate:
deadly haste.
extremely accurate:
Annie Oakley was a deadly shot.
in a manner resembling or suggesting death:
deadly pale.
excessively; completely:
deadly dull.
Origin of deadly
before 900; Middle English deedli(ch), Old English dēadlīce. See dead, -ly
Related forms
deadliness, noun
nondeadly, adjective
Can be confused
deadly, deathly.
1. See fatal. 4. dull, tedious, tiresome. Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2015.
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Examples from the web for deadly
  • Swift was a master satirist, and his irony was deadly.
  • What was once the stuff of science fiction, the recipe for creating deadly viruses, is now a frighteningly real possibility.
  • As deadly boring as these commencements can be, they can also be quite charming.
  • Natural disasters and nuclear power plants are a deadly mix.
  • Anything that might suggest that the writer has reservations on the candidate is also deadly.
  • The scientists are working on a way to make patients resistant to any deadly allergic reactions caused by the protein.
  • They're deadly, but taste utterly fantastic and are addictive.
  • Some of those poor outcomes included brain hemorrhages, which can be deadly, and failure of the patient to improve.
  • Among these species is an elite group of twelve mammals and reptiles equipped with a deadly arsenal of predatory skills.
  • But when the deadly wave receded, it sucked the occupants into a large culvert.
British Dictionary definitions for deadly


adjective -lier, -liest
likely to cause death: deadly poison, deadly combat
(informal) extremely boring
adverb, adjective
like death in appearance or certainty: deadly pale, a deadly sleep
Derived Forms
deadliness, noun
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
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Word Origin and History for deadly

Old English deadlic "mortal, subject to death," also "causing death;" see dead + -ly (1). Meaning "having the capacity to kill" is from late 14c. (Old English words for this included deaðbærlic, deaðberende).

Online Etymology Dictionary, © 2010 Douglas Harper
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Slang definitions & phrases for deadly


  1. Boring; extremely tedious; dull as death itself: I came prepared for a long and deadly meeting (1300+)
  2. Excellent; admirable; cool (1940s+ Swing talk)

Extremely: She is deadly serious about it (1300+)

The Dictionary of American Slang, Fourth Edition by Barbara Ann Kipfer, PhD. and Robert L. Chapman, Ph.D.
Copyright (C) 2007 by HarperCollins Publishers.
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