In English, the word skull means, well, of course, a human skull. Nothing weird.
In Swedish, there is a word "skalle" which means also skull but then there's also "döds skalle" which means deaths skull. This is a skull that is no longer attached to a living being, stripped down to the bone. I believe this is also the same in German with totenkopf.
But then in Finnish there is the word "pääkallo" which means head skull?!? Is there some other kind of skull?
What even are language.