The term 'Great Surge' is a reference to the period of rapid economic growth that occurred in the United States during the 1950s and 1960s. The term is often used to describe the period of time when the US economy was booming, with high levels of employment, rising wages, and increased consumer spending. The crossword solution for this term is 'ONRUSH, ' which is defined as a sudden, strong, and overwhelming rush or flow of something. This term accurately describes the period of economic growth during the Great Surge, as it was a period of rapid and overwhelming economic expansion.