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

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.

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

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

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.

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

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.

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

Oct 8, 2025 · deadly (comparative deadlier or more deadly, superlative deadliest or most deadly) (obsolete, rare) Subject to death; mortal. quotations

Some common synonyms of deadly are fatal, lethal, and mortal. While all these words mean "causing or capable of causing death," deadly applies to an established or very likely cause of …