Source : Webster's Revised Unabridged Dictionary (1913)

Uniat \U"ni*at\, Uniate \U"ni*ate\, n. (Eccl.)
   A member of the Greek Church, who nevertheless acknowledges
   the supremacy of the Pope of Rome; one of the United Greeks.
   Also used adjectively.

Source : WordNet®

Uniate
     adj : of or relating to former Eastern Christian or Orthodox
           churches that have been received under the jurisdiction
           of the Church of Rome but retain their own rituals and
           practices and canon law

Uniate
     n : a member of the Uniat Church [syn: {Uniat}, {Uniate
         Christian}]