fortissimo

adj, adv (abbr 缩写 ff) (music 音) very loud; (to be) played very loudly 最强音（的）; 用最强音演奏（的）.

formulaic, formulate, formulation, fornicate, fornication, forsake, forsaken, forseeable, forswear, forsythia, fort, forte, forth, forthcoming, forthright, forthwith, fortieth, fortification, fortified wine, fortify, fortitude, fortnight, fortnightly, FORTRAN (also Fortran), fortress, fortuitous, fortuity, fortunate, fortunately, fortune, fortune cookie, fortune-hunter, fortune-teller, forty, forty-five (also 45), forum, forward, forward-looking, forwarding address, forwarding agent,