trisagion /tri-sagˈi-on/

1. An ancient hymn consisting of the words ‘O Holy God, holy and mighty, holy and immortal, have mercy on us’
2. Loosely, the Tersanctus

• foes
• foetal
• foetal alcohol syndrome
• foeticidal
• foeticide
• foeticides
• foetid
• foetider
• foetidest
• foetidness
• foetidnesses
• foetor
• foetors
• foetoscopies
• foetoscopy
• foetus
• foetuses
• fog
• fogash
• fogashes
• fog bank
• fog banks
• fog-bell
• fog-bells
• fogbound