Rus·sian (rŭsh′ən) adj. 1. Of or relating to Russia or its people, language, or culture. 2. Of or relating to the former Soviet Union. n. 1. a. A native or inhabitant of Russia. b. A person of Russian ancestry. c. A native or inhabitant of the former Soviet Union. 2. The East Slavic language of the Russians, used as the official language of Russia …