What does Jackson mean in french?

Answer 1

Nothing, it is purely an English word, there is equivalent "last name" + "son" notation in French names like there is for instance for "Jansen" or "Johannson" names in some Scandinavian countries, because the form "son of" cannot be shortened as a " 's son " suffix as in English, and we also tend to refer to families by their last name, not by the first name of the father.

So, no "FilsdeJacques" (Jack's son) in French.

Answer 2

"Jackson" in French would be spelled the same and would be pronounced similarly to the English version.