forwarn or forewarn /fər- or för-wörnˈ/

To forbid

• flutter-tonguing
• fluttery
• fluty
• fluvial
• fluvialist
• fluvialists
• fluviatic
• fluviatile
• fluvioglacial
• flux
• flux densities
• flux density
• fluxed
• fluxes
• fluxing
• fluxion
• fluxional
• fluxionary
• fluxionist
• fluxionists
• fluxions
• fluxive
• fly
• flyable
• fly agaric