Add to word list dangerous and able to kill: a deadly poison (Definition of deadly from the Cambridge Academic Content Dictionary © Cambridge University Press)

1. causing or tending to cause death; lethal. 2. aiming to kill or destroy; implacable: a deadly enemy. 3. like death. 4. excruciatingly boring. 5. excessive; inordinate: deadly haste.

If you describe a person or their behaviour as deadly, you mean that they will do or say anything to get what they want, without caring about other people.

Something that's deadly can kill you. Because a gun can end someone's life, it's a deadly weapon.

Definition of deadly adjective in Oxford Advanced Learner's Dictionary. Meaning, pronunciation, picture, example sentences, grammar, usage notes, synonyms and more.

Synonyms: deathly, fatal, lethal, mortal, killer, more... Collocations: a deadly [virus, illness], a deadly attack on [Paris], the deadly attack on [Monday], more...

deadly (comparative deadlier or more deadly, superlative deadliest or most deadly) (obsolete, rare) Subject to death; mortal.

deadly, adj. & n. meanings, etymology, pronunciation and more in the Oxford English Dictionary

deadly, adj. & n. meanings, etymology and more | Oxford English Dictionary

Deadly refers to something that is likely to cause or is capable of causing death; lethal, fatal, or life-threatening. It can also refer to something highly dangerous, ominous or with adverse effects.

deadly, mortal, fatal, lethal mean causing or capable of causing death. deadly applies to an established or very likely cause of death.