sexennial /sek-senˈyəl or -senˈi-əl/

1. Lasting six years
2. Recurring every six years

sexennˈially adverb

• sea robins
• sea rocket
• sea rockets
• sea room
• sea rooms
• sea rosemary
• sea rover
• sea rovers
• sea-roving
• sears
• seas
• sea salmon
• sea salt
• sea salts
• sea sand
• sea sands
• sea satyre
• seascape
• seascapes
• sea scorpion
• sea scorpions
• Sea Scout
• Sea Scouts
• sease
• seased