Where does “is” come from?

is (Translingual) comes from Icelandic Ísland, from Old Norse Ísland, from Old Norse íss, from Proto-Germanic īsą, from Proto-Indo-European h₁eyH- — ice, frost.

Ancestry of “is”, step by step

Step	Language	Word	Meaning
1	Icelandic	Ísland	Iceland
2	Old Norse	Ísland	Iceland
3	Old Norse	íss	ice
4	Proto-Germanic	īsą	ice
5	Proto-Indo-European	h₁eyH-	ice, frost

Every word from Proto-Indo-European h₁eyH- →Every word from Proto-Germanic īsą →Every word from Old Norse íss →