Where does “膜” come from?

膜 (Chinese) comes from Chinese 南膜, from Sanskrit नमस्, from Proto-Indo-European némos, from Proto-Indo-European nem- — to distribute; to give, to take.

Ancestry of “膜”, step by step

Step	Language	Word	Meaning
1	Chinese	南膜	Alternative form of 南無／南无
2	Sanskrit	नमस्	bow, obeisance, reverential salutation,...
3	Proto-Indo-European	némos	sacrifice, worship; place of sacrifice, clearing
4	Proto-Indo-European	nem-	to distribute; to give, to take

Every word from Proto-Indo-European nem- →

膜 — Etymology, Origin & Word History | Etymology Explorer