> ethnonationalism—an ideology that defines national belonging through shared ancestry, culture, and language
'ethno' is superfluous - 'nation' has been defined that way for millennia:
nation(n.) - c. 1300, nacioun, "a race of people, large group of people with common ancestry and language," from Old French nacion "birth, rank; descendants, relatives; country, homeland" (12c.) and directly from Latin nationem (nominative natio) "birth, origin; breed, stock, kind, species; race of people, tribe," literally "that which has been born," from natus, past participle of nasci "be born" (Old Latin gnasci), from PIE root *gene- "give birth, beget," with derivatives referring to procreation and familial and tribal groups.
> ethnonationalism—an ideology that defines national belonging through shared ancestry, culture, and language
'ethno' is superfluous - 'nation' has been defined that way for millennia:
nation(n.) - c. 1300, nacioun, "a race of people, large group of people with common ancestry and language," from Old French nacion "birth, rank; descendants, relatives; country, homeland" (12c.) and directly from Latin nationem (nominative natio) "birth, origin; breed, stock, kind, species; race of people, tribe," literally "that which has been born," from natus, past participle of nasci "be born" (Old Latin gnasci), from PIE root *gene- "give birth, beget," with derivatives referring to procreation and familial and tribal groups.
https://www.etymonline.com/word/nation