hyphenismn.

/ˈhʌɪfənɪz(ə)m/Etymology: < hyphen n. + -ism suffix; compare hyphenated adj. 2.
U.S.the world > people > nations > national of a country > [noun] > persons of two nations > state of being
1930 P. W. Slosson (1931) xi. 288 The years..so marked by hyphenism and the echoes of Old World feuds.
This entry has not yet been fully updated (first published 1976; most recently modified version published online June 2018).