Jósteinn (Old Norse) comes from Old Norse steinn, from Proto-Norse ᛊᛏᚨᛁᚾᚨᛉ, from Proto-Germanic stainaz, from Proto-Indo-European steyh₂-, from Proto-Indo-European steh₂- — to stand.
Ancestry of “Jósteinn”, step by step
Jósteinn traces back through two separate lines of ancestry.