vicennial /vī-senˈyəl/

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

• catenary
• catenas
• catenate
• catenated
• catenates
• catenating
• catenation
• catenations
• catenoid
• catenoids
• cater
• cateran
• caterans
• catercorner
• catercornered
• cater-cousin
• cater-cousins
• catered
• caterer
• caterers
• cateress
• cateresses
• catering
• caterings
• caterpillar