Try Our Apps


Avoid these words. Seriously.


[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. 2018.
Cite This Source
Examples from the Web for deadliness
Contemporary Examples
Historical Examples
  • There was the deadliness of the story: its lack of malice, even of resentment.

    Alice Adams Booth Tarkington
  • Silently and with deadliness apparent in every move they approached him.

    In the Orbit of Saturn Roman Frederick Starzl
  • Slander nips it like a frost; in deadliness it is second only to ridicule.

    Mistress Wilding Rafael Sabatini
  • But the knowledge of his deadliness kept him from being made a target.

    When the West Was Young Frederick R. Bechdolt
  • As to Navel-ill, much has been written on the deadliness of the complaint.

    Cattle and Cattle-breeders William M'Combie
  • He was deadly quiet about it; and the deadliness and quietness subdued her.

    The Combined Maze May Sinclair
  • The only difference between them is the varying degree of deadliness.

    Deathworld Harry Harrison
  • The deadliness that had been in the gray eyes was in the voice now.

    Bulldog Carney W. A. Fraser
  • But there was one circumstance which gave it a deadliness all its own.

    The Man Upstairs P. G. Wodehouse
British Dictionary definitions for deadliness


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
Cite This Source
Word Origin and History for deadliness



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
Cite This Source
Slang definitions & phrases for deadliness



  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.
Cite This Source

Word of the Day

Nearby words for deadliness

Word Value for deadliness

Scrabble Words With Friends