Probably from etho; a race (as of the same habit), i.e. A tribe; specially, a foreign (non-Jewish) one (usually, by implication, pagan) -- Gentile, heathen, nation, people.

see GREEK etho

ἔθνει (ethnei) − 7 Occurrences

ἔθνεσιν (ethnesin) − 32 Occurrences

ἔθνη (ethnē) − 52 Occurrences

ἔθνος (ethnos) − 18 Occurrences

ἔθνους (ethnous) − 7 Occurrences

ἐθνῶν (ethnōn) − 46 Occurrences