The Soviet Union was a Marxist-Leninist state that existed from 1922 to 1991. It was a one-party state governed by the Communist Party of the Soviet Union, and its official language was RUSSIAN. The term 'Soviet' is derived from the RUSSIAN word for council, soviet. The Soviet Union was a major world power during the Cold War ERA, and it was composed of 15 constituent republics. The RUSSIAN word for Russia is 'Rossiya', which is the answer to the crossword clue 'RUSSIAN' (7 letters). The 'ERA' (3 letters) refers to the period of Soviet history from 1922 to 1991. The 'BLOC' (4 letters) refers to the Eastern BLOC, a group of countries in Eastern Europe that were allied with the Soviet Union during the Cold War. The 'SINO' (4 letters) refers to the Sino-Soviet split, a period of tension between the Soviet Union and the People's Republic of China that lasted from the late 1950s to the early 1980s.