adj. Of, relating to, or characteristic of a sizable group of people sharing a common and distinctive racial, national, religious, linguistic, or cultural heritage.adj. 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. adj. 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.