Where does “immūnis” come from?

immūnis (Latin) comes from Latin in- -is, from Latin īn-, from Latin în, from Latin en, from Proto-Italic en, from Proto-Indo-European h₁én — in.

immūnis (Latin): free or exempt from taxes, public service, or penalty (+ ablative)

Definitions

immūnis traces back through two separate lines of ancestry.

Step	Language	Word	Meaning
1	Latin	in- -is	less, without, lacking
2	Latin	īn-	un-, non-, not
3	Latin	în	in, at, on, upon, from (space)
4	Latin	en	lookǃ beholdǃ; reallyǃ?; come onǃ
5	Proto-Italic	en	in
6	Proto-Indo-European	h₁én	in

Step	Language	Word	Meaning
1	Latin	mūnus	a service, office, employment
2	Proto-Italic	moinos	service
3	Proto-Indo-European	moynós	—