And with the Christians it becomes an equivalent of goy, goyim, but without including Israelites, of course.Here is what Gerard Jeanneau's Prima Elementa has to say about it.
Nātĭo, ōnis, f. [nascor, natus]: - 1 - birth. - 2 - race, offspring, species, kind. - 3 - nation, people. - 4 - plural. nations, pagans, gentiles.
-nationu (= nationis) cratia (= gratia) donom dedi, CIL 2, 60: I have made this gift [to Fortune] because of a birth.
-natione Medus, Nep. Medus by birth.
-Natio (Nascio), ōnis, f.: Nation (goddess who presided over birth).
-Natio quoque dea putanda est, Cic. Nat. 3, 47: Nation also to be considered a goddess.
-omnes nationes servitutem ferre possunt, nostra civitas non potest, Cic. Phil. 10, 10, 20: all other nations can suffer slavery, our city cannot. cf. id. Font. 11, 25; Nat. 3, 39, 93.
-omnes exteræ gentes ac nationes, Cic. Imp. Pomp. 11, 31: all the countries in the world, all the peoples. --- cf. Quint. 11, 3, 87; Cic. de Or. 2, 4, 18; id. Prov. Cons. 5, 10; id. Q. Fr. 1, 1, 9, § 27; Cæs. BG. 3, 7; Tac. G. 38; id. An. 11, 18.
-nationem reddere deteriorem, Varr. R. 2, 6, 4: to harm the litter (of an ass).
-bona natio, P. Fest. : abundant litter, great fecundity.
-nationes, Plin. 22, 109 : varieties (of bees).
-nationes ceræ, Plin. : different species of wax.
-natio officiosissima candidatorum, Cic. Pis. 23, 55 : the candidates, very obsequious people.
-famelica hominum natio, Plaut. : half-starved brood.
-omnes ejus gentis nationes, Tac. all the peoples in this country.
-nationes, Tert. Id. 22: the pagans, the gentiles.
-ante aditum porticūs Ad Nationes, Plin. 36, 39: before the entrance to the portico of Nations. cf. Serv. Virg. En. 8, 721 (portico decorated with statues representing all the nations).
It should be noted that the broadening of the meaning only really began with the Church Latin (Tertullian) which made it an equivalent of goy, goïm, but non-including the Jews.
Other etymological dictionary online.
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.
The word is used in English in a broad sense, "a race of people an aggregation of persons of the same ethnic family and speaking the same language."
But now, the influencers in this country prefer to think through oxymorons (sic)
and also in the narrower sense, "a political society composed of a government and subjects or citizens and constituting a political unit; an organized community inhabiting a defined territory within which its sovereignty is exercised."
Point No. 5 of the reasoning.
METHODOLOGY.
When did it stop being reasonable to call the inhabitants of Manhattan Leni Lenape or Munsee? From the passage of the French in 1524? In 1613 with the Dutch?
You'd have to ask the people of the Ramapough Mountains. Or Fenimore Cooper. 5)
After a certain number of changes, an "existing one" ceases to be reasonably designated by the name that suited its ancestors.