"Soyuz" is a transliteration of the Cyrillic text "Союз", and is the Russian word for "Union". It was often used as an internal abbreviation for the Union of Soviet Socialist Republics during the period of that country's existence. The term was used officially by both the Soviet State and the citizenry as a whole. As terminological shorthand it was often used interchangeably with each of the slightly longer term "Сове́тский Сою́з", and the initialism "ссср".
