Where does “proethnic” come from?

proethnic (English) comes from English ethnic, from French ethnique, from Middle French ethnique, from Old French ethnique, from Latin ethnicus, from Ancient Greek ἐθνικός, from Ancient Greek ἔθνος, from Ancient Greek ἔθω — to do, put, place.

proethnic (English): of or pertaining to the period prior to the split of the Proto-Indo-European language into the Indo-European language family

Definitions

of or pertaining to the period prior to the split of the Proto-Indo-European language into the Indo-European language family

Ancestry of “proethnic”, step by step

Step	Language	Word	Meaning
1	English	ethnic	Of or relating to a group of people having common...
2	French	ethnique	ethnic
3	Middle French	ethnique	—
4	Old French	ethnique	—
5	Latin	ethnicus	heathen; pagan
6	Ancient Greek	ἐθνικός	national
7	Ancient Greek	ἔθνος	group of people: tribe, family; group of animals:...
8	Ancient Greek	ἔθω	I am accustomed, I tend to
9	Proto-Indo-European	swe-dʰh₁-	—
10	Proto-Indo-European	dʰeh₁-	to do, put, place

Every word from Proto-Indo-European dʰeh₁- →Every word from Proto-Indo-European swe-dʰh₁- →Every word from Ancient Greek ἔθω →