"As Dead As a Dodo"

Have you ever heard people saying that something is as dead as a dodo? What is the meaning of this phrase? Does it have any easy-to-trust origin? If yes, so what it can be?

Firstly, let's look "dodo" up in the dictionary. There it is written:
Dodo= A large bird that was unable to fly and no longer exists.

Now it became a bit clear that dodo was the name of an animal. This animal was probably large, and incapable of flying, which is also extinct today. In reality, our unknown dodo lived on the islands of Mauritius. Its meat was not tasty or yummy, but hunters killed a lot of them yonks ago. So, that is why this is nearly the first time you are hearing about dodo.

In short, when we say something is as dead as a dodo we do mean that thing is not active, alive, and in use any more. Although, dodo is not extant today this phrase effortlessly encourages you and me to remember that large quiet bird forever.