octingenary /ok-tin-jēˈnə-ri/ or octingentenary /-jen-tēˈnə-ri/

An eight-hundredth anniversary

• undercut
• undercuts
• undercutting
• underdamper
• underdampers
• underdeck
• underdecks
• underdevelop
• underdeveloped
• underdeveloping
• underdevelopment
• underdevelops
• underdid
• underdo
• underdoer
• underdoers
• underdoes
• underdog
• underdogs
• underdoing
• underdone
• underdrain
• underdrained
• underdraining
• underdrains