vicennial /vī-senˈyəl/

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

• bomb-happy
• bombilate
• bombilated
• bombilates
• bombilating
• bombilation
• bombilations
• bombinate
• bombinated
• bombinates
• bombinating
• bombination
• bombinations
• bombing
• bombings
• bomb-ketch
• bomblet
• bomblets
• bombo
• bombora
• bomboras
• bombos
• bombproof
• bombproofs
• bombs