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

• foveoles
• fowl
• fowled
• fowler
• fowlers
• fowling
• fowling-net
• fowling-nets
• fowling-piece
• fowling-pieces
• fowlings
• fowl-pest
• fowl-pests
• fowl-plague
• fowls
• fowls of warren
• fowth
• fowths
• fox
• fox and geese
• fox-bat
• fox-bats
• foxberries
• foxberry
• fox-brush