eth·nic 
(ĕthnĭk)
(ĕthnĭk)adj.
1.
a. Of, relating to, or characteristic of a group of people sharing a common cultural or national heritage and often sharing a common language or religion.
b. Being a member of a particular ethnic group, especially belonging to a national group by heritage or culture but residing outside its national boundaries: ethnic Hungarians living in northern Serbia.
c. Of, relating to, or distinctive of members of such a group: ethnic restaurants; ethnic art.
2. Archaic Relating to a people not Christian or Jewish.
n.
A member of a particular ethnic group, especially one who maintains the language or customs of the group.
[Middle English, heathen, from Late Latin ethnicus, from Greek ethnikos, from ethnos, people, nation; see s(w)e- in the Appendix of Indo-European roots.]
Word History: When it is said in a Middle English text written before 1400 that a part of a temple fell down and "mad a gret distruccione of ethnykis," one wonders which ethnicity was singled out for death. The word ethnic in this context, however, means "gentile," coming as it does from the Greek adjective ethnikos, meaning "national, foreign, gentile." The adjective is derived from the noun ethnos, "people, nation, foreign people," that in the plural phrase ta ethnē meant "foreign nations." In translating the Hebrew Scriptures into Greek, this phrase was used for Hebrew gōyīm, "gentiles"; hence the sense of the noun in the Middle English quotation. The current sense of the word emerged in the 19th century, probably under the influence of other words going back to Greek ethnos, such as ethnography and ethnology.