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

• on this wise
• on time
• on tiptoe
• on to
• onto
• on toast
• ontogeneses
• ontogenesis
• ontogenetic
• ontogenetically
• ontogenetics
• ontogenic
• ontogenically
• ontogenies
• ontogeny
• ontologic
• ontological
• ontologically
• ontologies
• ontologist
• ontologists
• ontology
• on top of
• on top of the world
• ratched