lustrum
/ˈlʌstrəm/
noun
- A period of five years.
- He looked back over the past lustrum and saw how much his children had grown.
- The company's five-year plan covered the next lustrum of growth.
- Every lustrum, the town holds a festival to celebrate its history.
- In ancient Rome, a ceremonial purification of the population, held every five years.
- The Roman censors conducted a lustrum to purify the city after the census.
- During the lustrum, citizens gathered for sacrifices and prayers.
- Historians study the lustrum as an important religious and political event.