Dictionary
1deadly
adjective dead·ly \ˈded-lē\
: causing or able to cause death
: extremely accurate and effective
: extreme or complete
dead·li·erdead·li·est
Full Definition of DEADLY
1
: likely to cause or capable of producing death <deadly poison>
2
a : aiming to kill or destroy : implacable <a deadly enemy> b : highly effective <a deadly exposé> c : unerring <a deadly marksman> d : marked by determination or extreme seriousness
3
a : tending to deprive of force or vitality <a deadly habit> b : suggestive of death especially in dullness or lack of animation <deadly bores> <a deadly conversation>
See deadly defined for English-language learners
See deadly defined for kids
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First Known Use of DEADLY
before 12th century
Related to DEADLY
Synonym Discussion of DEADLY
deadly, mortal, fatal, lethal mean causing or capable of causing death. deadly applies to an established or very likely cause of death <a deadly disease>. mortal implies that death has occurred or is inevitable <a mortal wound>. fatal stresses the inevitability of what has in fact resulted in death or destruction <fatal consequences>. lethal applies to something that is bound to cause death or exists for the destruction of life <lethal gas>.
2deadly
adverb
: extremely or completely
Full Definition of DEADLY
1
archaic : in a manner to cause death : mortally
2
: suggesting death
3
: extremely <deadly serious>
See deadly defined for English-language learners
First Known Use of DEADLY
before 12th century
Related to DEADLY
- Synonyms
- achingly, almighty, archly, awful, awfully, badly, beastly, blisteringly, bone, colossally, corking, cracking, damn, damned, dang, very, desperately, eminently, enormously, especially, ever, exceedingly (also exceeding), extra, extremely, fabulously, fantastically, far, fiercely, filthy, frightfully, full, greatly, heavily, highly, hugely, immensely, incredibly, intensely, jolly, majorly, mightily, mighty, monstrous [chiefly dialect], mortally, most, much, particularly, passing, rattling, real, really, right, roaring, roaringly, seriously, severely, so, sore, sorely, spanking, specially, stinking, such, super, supremely, surpassingly, terribly, that, thumping, too, unco, uncommonly, vastly, vitally, way, whacking, wicked, wildly
- Antonyms
- little, negligibly, nominally, slightly, somewhat
DEADLY Defined for Kids
1deadly
adjective dead·ly \ˈded-lē\
dead·li·erdead·li·est
Definition of DEADLY for Kids
1
: causing or capable of causing death <deadly poisons>
2
: meaning or hoping to kill or destroy <deadly enemies>
3
: very accurate <He shot the arrow with deadly aim.>
4
: 1extreme 1
Synonym Discussion of DEADLY
deadly, mortal, and fatal mean causing or capable of causing death. deadly is used of something that is certain or very likely to cause death. <The mushroom contains a deadly poison.> mortal is used of something that already has caused death or is about to cause death. <He received a mortal wound in battle.> fatal is used when death is certain to follow. <The wounds proved to be fatal.>
2deadly
adverb
Definition of DEADLY for Kids
1
: in a way suggestive of death <Her face was deadly pale.>
2
: to an extreme degree <deadly dull>
Medical Dictionary
deadly
adjective dead·ly \ˈded-lē\
dead·li·erdead·li·est
Medical Definition of DEADLY
: likely to cause or capable of causing death <a deadly disease> <a deadly poison> <a deadly instrument>
—dead·li·ness \-nəs\ noun
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