Questions about example sentences with, and the definition and usage of "Deadly"

A: That it can kill you.

A: deadly is slang for very/extemely while accurate means precise. so them saying that is them practically saying "very precise or extremely accurate."

A: deadly means dangerous and possibly could kill

A: It could kill you.

A: "Deadly dull" is another way of saying "very/extremely boring" or even "very/extremely average."

"Dull" is used to describe something that is boring or average. And "deadly" can be used to emphasize some adjectives.

A: Deadly means it could possibly kill you.
Fatal means it will kill you or already has killed you.

A: They all mean the same thing! You can use them interchangeably

A: “Deadly” and “lethal” are very similar in meaning, but there is some difference.

“Deadly” simply means something that causes death.

“Lethal” means something that is over the minimum amount required in order to cause death.

For example, “The research center applied a lethal dose of poison to the mice’s food.” makes slightly more sense than “The research center applied a deadly dose of poison to the mice’s food.” because “lethal” helps the reader specifically understand that the goal of the dose was to cause the death of the mice.
The amount of poison was lethal because it exceeded the minimum amount of poison required to cause death in the mice.
“Deadly” is not incorrect here, but it is imprecise in meaning. It simply means that it caused death.

“Lethal” helps the reader know that the researchers were thinking about the amount of poison necessary during their research experiment.
“Deadly” can also be used here, but is less clear, and less formal. It may sound more like the researchers were not thinking about the amount of poison applied, which happened to be enough to cause death anyway.

Because the meanings are so similar, they are often used interchangeably.
If you are writing for academic or research purposes, it’s probably better to use the word “lethal” to mean something that is known to be capable of causing death.

An example where “deadly” may be more appropriate would be:
“The woman tried to escape the storm, but eventually found herself in a deadly situation when she was struck by lightning.”

This is because it is not clear how much lightning is enough to cause death, and because the situation has so many different aspects that affect the likelihood of death.
The lightning ultimately caused death, so it was a deadly situation.
If you want to use “lethal” for this situation, the best way would be to say something like “the strength of the lightning was lethal”, which means the strength of the lightning strike was over the minimum amount required to cause death.

In any sentence, you can almost always use them interchangeably, and people will understand. But, for the most precise usage, consider the examples and decide whether you want to talk about the amount necessary to cause death (lethal) or simply whether it did or did not cause death (deadly).

A: thank you

A: 死にそうなくらいの暑さ

A: Sounds awesome!

A: I would say "I'm dead tired"

A: Most people would say, "deathly".