Where does “自宅警備員” come from?

自宅警備員 (Japanese) comes from Japanese 警備員, from Japanese 員, from Middle Chinese 員.

自宅警備員 (Japanese): recluse: NEET, hikikomori, etc

Definitions

recluse: NEET, hikikomori, etc

Ancestry of “自宅警備員”, step by step

自宅警備員 traces back through two separate lines of ancestry.

via Japanese 警備員

Step	Language	Word	Meaning
1	Japanese	警備員	guard, guardsman
2	Japanese	員	member
3	Middle Chinese	員	—

via Japanese 自宅

Step	Language	Word	Meaning
1	Japanese	自宅	one's own home

Every word from Middle Chinese 員 →Every word from Japanese 員 →Every word from Japanese 警備員 →