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

• brakes
• brake shoe
• brake shoes
• brakesman
• brake van
• brake vans
• brake-wheel
• brake-wheels
• brakier
• brakiest
• braking
• braky
• braless
• Bramah-lock
• Bramah-press
• bramble
• bramble-berries
• bramble-berry
• bramble-bush
• bramble-bushes
• brambled
• bramble-finch
• bramble-finches
• brambles
• bramblier