vicennial /vī-senˈyəl/

1. Lasting, or coming at the end of, twenty years
2. Occurring every twenty years

• master aircrews
• master-at-arms
• masterate
• masterates
• master-builder
• master-builders
• master-card
• master-cards
• MasterCard®
• master-class
• master-classes
• master-clock
• master-clocks
• masterdom
• masterdoms
• mastered
• masterful
• masterfully
• masterfulness
• masterfulnesses
• master-hand
• master-hands
• masterhood
• masterhoods
• masteries