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

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.

Dec 22, 2016 · 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.

Dec 21, 2025 · deadly (comparative deadlier or more deadly, superlative deadliest or most deadly) (obsolete, rare) Subject to death; mortal. quotations

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

deadly, mortal, fatal, and lethal mean causing or able to cause death. deadly describes something that is very dangerous and likely or able to cause death.

DEADLY definition: causing or tending to cause death; fatal; lethal. See examples of deadly used in a sentence.

deadly definition: causing or able to cause death. Check meanings, examples, usage tips, pronunciation, domains, and related words. Discover expressions like "deadly earnest", …

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