1. occurring every ten years
2. lasting for ten years

1. a tenth anniversary or its celebration

Examples

• The decennial census is conducted every ten years.
• The university celebrated its decennial anniversary with a special ceremony.
• Decennial population surveys help track demographic changes.
• The company’s decennial review showed steady growth.
• They planned a grand celebration for the organization’s decennial.
• The decennial report summarized a decade of progress.