Where does “Irlanti” come from?

Irlanti (Finnish) comes from Swedish Irland, from Old Norse Írland, from Old Norse Írar, from Old Irish Ériu, from Primitive Irish *Īweriū, from Proto-Celtic Φīweryū, from Proto-Indo-European piHweryon-, from Proto-Indo-European peyH- — fat, milk.

Irlanti (Finnish): the Irish language