septennial
/sɛpˈtɛniəl/
adjective
- Occurring once every seven years.
- The club holds a septennial reunion for all former members.
- The septennial census provides a snapshot of population changes.
- Their septennial festival is a major event in the town.
- Lasting for a period of seven years.
- The septennial contract was renewed after negotiations.
- The king signed a septennial truce with the neighboring kingdom.
- They signed a septennial lease on the office building.