The term 'Period of Prosperity' can be described by two crossword solutions: 'BOOM' (4 letters) and 'Goldenage' (9 letters). A 'BOOM' is a period of rapid economic growth, often accompanied by increased investment and consumer spending. A 'golden age' is a period of time in which a particular activity or area of knowledge is at its peak. Together, these two terms describe a period of great economic success and cultural advancement.