Where does “inpugnaturus” come from?

inpugnaturus (Latin) comes from Latin inpugno, from Latin impugno, from Latin in-, from Latin in, from Old Latin en, from Proto-Italic en, from Proto-Indo-European h₁én — in.

Definitions

Ancestry of “inpugnaturus”, step by step

Step	Language	Word	Meaning
1	Latin	inpugno	Alternative form of impugnō
2	Latin	impugno	I attack, fight against; I impugn, assail
3	Latin	in-	un-, non-, not; in, within, inside
4	Latin	in	in, at, on, upon, from; within, while in; into,...
5	Old Latin	en	in
6	Proto-Italic	en	in
7	Proto-Indo-European	h₁én	in

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