Princeton's WordNet (5.00 / 1 vote) Rate this definition: ethnic (adj). a person who is a member of an ethnic group. cultural, ethnic, ethnical (adj). denoting or deriving from or distinctive of the ways of living built up by a group of people.iktionary (0.00 / 0 votes) Rate this definition: ethnic (Noun). An ethnic person, notably said when a foreigner or member of an immigrant community. ethnic (Noun). An ethnic minority. ethnic (Noun). A heathen, a pagan. ethnic (Adjective).