Interethnic

[eth-nik] /ˈɛθ nɪk/

adjective
1.
pertaining to or characteristic of a people, especially a group (ethnic group) sharing a common and distinctive culture, religion, language, or the like.
2.
referring to the origin, classification, characteristics, etc., of such groups.
3.
being a member of an ethnic group, especially of a group that is a minority within a larger society:
ethnic Chinese in San Francisco.
4.
of, relating to, or characteristic of members of such a group.
5.
belonging to or deriving from the cultural, religious, or linguistic traditions of a people or country:
ethnic dances.
6.
(of a human being) displaying characteristics, as in physical appearance, language, or accent, that can cause one to be identified by others as a member of a minority ethnic group:
Her new boyfriend looks ethnic to me.
7.
Obsolete. pagan; heathen.
noun
8.
a member of an ethnic group.
/ˈɛθnɪk/
adjective
1.
relating to or characteristic of a human group having racial, religious, linguistic, and certain other traits in common
2.
relating to the classification of mankind into groups, esp on the basis of racial characteristics
3.
denoting or deriving from the cultural traditions of a group of people: the ethnic dances of Slovakia
4.
characteristic of another culture: the ethnic look, ethnic food
noun
5.
(mainly US & Austral) a member of an ethnic group, esp a minority group
n.

late 14c., Scottish, “heathen, pagan,” and having that sense first in English; as an adj. from late 15c. from Latin ethnicus, Greek ethnikos, from ethnos “band of people living together, nation, people,” properly “people of one’s own kind,” from PIE *swedh-no-, suffixed form of root *s(w)e- (see idiom).

In Septuagint, Greek ta ethne translates Hebrew goyim, plural of goy “nation,” especially of non-Israelites, hence “Gentile nation” (see goy). Sense of “peculiar to a race or nation” is attested from 1851, a return to the word’s original meaning; that of “different cultural groups” is 1935; and that of “racial, cultural or national minority group” is American English 1945; ethnic cleansing is attested from 1991.

Although the term ‘ethnic cleansing’ has come into English usage only recently, its verbal correlates in Czech, French, German, and Polish go back much further. [Jerry Z. Muller, “Us and Them: The Enduring Power of Ethnic Nationalism,” Foreign Affairs, March/April 2008]