in biblical Greek "Gentile" is the word Ethnos
Strongs word study concordance/Concordance
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ἔθνος ĕthnŏs, eth´-nos; prob. from 1486; a race (as of the same habit), i.e. a tribe; spec. a foreign (non-Jewish) one (usually by impl. pagan):—Gentile, heathen, nation, people.
Strong, J. (2009). A Concise Dictionary of the Words in the Greek Testament and The Hebrew Bible (Vol. 1, p. 25). Bellingham, WA: Logos Bible Software.