Where does “Zēlande” come from?

Zēlande (Latvian) comes from Dutch zeeland, from Middle Dutch Sêelant.

Ancestry of “Zēlande”, step by step

Step	Language	Word	Meaning
1	Dutch	zeeland	land adjacent to the sea, coastal land
2	Middle Dutch	Sêelant	—

Zēlande — Etymology, Origin & Word History | Etymology Explorer