Where does “immun” come from?

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

Ancestry of “immun”, step by step

Step	Language	Word	Meaning
1	Latin	immūnis	free or exempt from taxes, public service, or penalty (+ ablative)
2	Latin	in- -is	less, without, lacking
3	Latin	īn-	un-, non-, not
4	Latin	în	in, at, on, upon, from (space)
5	Latin	en	lookǃ beholdǃ; reallyǃ?; come onǃ
6	Proto-Italic	en	in
7	Proto-Indo-European	h₁én	in

Words derived from “immun”

immun
immuun
imun
immuunsysteem
autoimun
imun

Every word from Proto-Indo-European h₁én →Every word from Latin īn- →Every word from Proto-Italic en →