ff or ff.

1. Fecerunt (Latin), (they) did it or made it
2. Folios (printing)
3. Following pages, lines, etc
4. Fortissimo (music)

FF

1. Form feed (computing)
2. French franc or francs

• hierologists
• hierology
• hieromancies
• hieromancy
• Hieronymian
• Hieronymic
• Hieronymite
• hierophant
• hierophantic
• hierophants
• hierophobia
• hierophobias
• hierophobic
• hieroscopies
• hieroscopy
• Hierosolymitan
• hierurgical
• hierurgies
• hierurgy
• hies
• hi-fi
• Hi-Fi
• hi-fis
• higgle
• higgled