Where does “شن” come from?

شن (Ottoman Turkish) comes from Armenian շեն, from Old Armenian շէն, from Middle Iranian šēn.

Ancestry of “شن”, step by step

Step	Language	Word	Meaning
1	Armenian	շեն	inhabited, peopled; undamaged, intact, unharmed;...
2	Old Armenian	շէն	inhabited place; village, hamlet; inhabitation;...
3	Middle Iranian	šēn	—

شن — Etymology, Origin & Word History | Etymology Explorer