Where does “immune” come from?

immune (Latin) comes from Latin immunis, from Latin in-, from Latin in, from Old Latin en, from Proto-Italic en, from Proto-Indo-European h₁én — in.

immune (Latin): nominative neuter singular of immūnis; accusative...

Definitions

Step	Language	Word	Meaning
1	Latin	immunis	free or exempt from taxes or public service;...
2	Latin	in-	un-, non-, not; in, within, inside
3	Latin	in	in, at, on, upon, from; within, while in; into,...
4	Old Latin	en	in
5	Proto-Italic	en	in
6	Proto-Indo-European	h₁én	in