[Dylan16807]

We can put bounds on it.

Here's an easy lower bound, for the context of avoiding collisions: The name has to have been used by at least two different humans.

Or to get closer to a reasonable bound, 100 humans.

[BlueTemplar]

How would you know how much it has been used ?

We don't even have a database for all the humans alive today, much less one for the last 400 000 years...

[Dylan16807]

You can be pretty confident without a comprehensive database. If you're unsure about a name then don't pick that one.

And people that are dead won't be inconvenienced, so you can ignore them.

[jodrellblank]

People (and lawyers) might get annoyed if you called your bot Avici, even though he is dead and won’t personally be inconvenienced by it.

[Dylan16807]

Naming something after a celebrity is a different issue entirely. It's actually a bigger problem if the celebrity has a non-regular name!