a member of an Eastern church that is in union with the Roman Catholic Church, acknowledges the Roman pope as supreme in matters of faith, but maintains its own liturgy, discipline, and rite.
Origin: 1825–35; < Ukrainian uni(y)át, equiv. to úni(ya) the Union of Brest-Litovsk (1596), an acceptance of papal supremacy by some Orthodox clerics in Poland (< Pol uni(j)a < L ūniōunion) + -(y)at ≪ L -ātus-ate1
U·ni·at (yōō'nē-āt', -ĭt) adj. Of or relating to any of several Eastern Christian churches that are in communion with the Roman Catholic Church but retain their own languages, rites, and codes of canon law. n. A member of any of these churches.
[Russian uniyat, from Polish uniat, the Union of Brest-Litovsk (1596), from unija, union, from Late Latin ūniō; see union.]
"pertaining to an Eastern Christian church that acknowledges the supremacy of the Pope," 1833, from Rus. uniyat, from unia "unity, union," from L. unus "one" (see one).