Definitions

1. noun

The former Soviet Union, a country that existed from 1922 to 1991, comprising Russia and 14 other Soviet Socialist Republics.

“The breakup of the USSR led to the rise of independent nations in Eastern Europe.”

2. proper noun

The Soviet Union, a country that existed from 1922 to 1991, comprising Russia and 14 other Soviet Socialist Republics.

“The leaders of the USSR played a significant role in the Cold War.”