triduum /tridˈū-əm or trīˈdū-/ (esp RC)

1. A space of three days
2. A period of prayer or religious celebration lasting three days

• ground controls
• ground cover
• ground covers
• ground crew
• ground crews
• ground-cuckoo
• ground-cuckoos
• ground-dove
• ground-doves
• grounded
• groundedly
• ground effect
• ground effects
• ground elder
• grounden
• grounder
• grounders
• ground-feeder
• ground-feeders
• ground floor
• ground floors
• ground frost
• ground game
• ground glass
• groundhog