What you are seeking is called a "euphemism"-- a polite way to say something that is considered a "bad" word. The most common euphemism these days is "the F bomb." (In radio, disc jockeys are often reminded not to "drop the F bomb" while on the air.) Some people also use "fudge," or they hint about the word-- "the word that begins with F and rhymes with truck."
According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 2 words with the pattern --LA-F. That is, six letter words with 3rd letter L and 4th letter A and 6th letter F. In alphabetical order, they are: pilaff sclaff
According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 2 words with the pattern F--Z--Y. That is, seven letter words with 1st letter F and 4th letter Z and 7th letter Y. In alphabetical order, they are: frizzly fuzzily
According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 4 words with the pattern F--OS-. That is, six letter words with 1st letter F and 4th letter O and 5th letter S. In alphabetical order, they are: favose filose floosy fucose
According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 1 words with the pattern -F--I-T. That is, seven letter words with 2nd letter F and 5th letter I and 7th letter T. In alphabetical order, they are: afflict
According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 10 words with the pattern F----AR. That is, seven letter words with 1st letter F and 6th letter A and 7th letter R. In alphabetical order, they are: fabular facebar facular felspar fenitar fibular flatcar footbar forbear forecar
Fun, flawless and faithful are good words.
According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 1 words with the pattern F---FF. That is, six letter words with 1st letter F and 5th letter F and 6th letter F. In alphabetical order, they are: flyoff
According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 1 words with the pattern F-FFI---. That is, eight letter words with 1st letter F and 3rd letter F and 4th letter F and 5th letter I. In alphabetical order, they are: fuffiest
According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 1 words with the pattern F---F-A--. That is, nine letter words with 1st letter F and 5th letter F and 7th letter A. In alphabetical order, they are: flimflams
According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 1 words with the pattern F-F--I--. That is, eight letter words with 1st letter F and 3rd letter F and 6th letter I. In alphabetical order, they are: fiftyish
According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 1 words with the pattern I-F--F--. That is, eight letter words with 1st letter I and 3rd letter F and 6th letter F. In alphabetical order, they are: infeoffs
According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 3 words with the pattern F--FF. That is, five letter words with 1st letter F and 4th letter F and 5th letter F. In alphabetical order, they are: feoff flaff fluff
According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 2 words with the pattern --FF--FF. That is, eight letter words with 3rd letter F and 4th letter F and 7th letter F and 8th letter F. In alphabetical order, they are: niffnaff riffraff
6 letter f words ending with e:fiddlefacadefaminefeeblefoiblefelineficklefigurefinalefizzlefleecefondleforageforseefutilefreezefringefumble
According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 5 words with the pattern ---F-FF--. That is, nine letter words with 4th letter F and 6th letter F and 7th letter F. In alphabetical order, they are: carfuffle cuffuffle curfuffle kerfuffle kurfuffle
According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 1 words with the pattern -IF-F--. That is, seven letter words with 2nd letter I and 3rd letter F and 5th letter F. In alphabetical order, they are: lifeful
According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 1 words with the pattern --IF----F-. That is, ten letter words with 3rd letter I and 4th letter F and 9th letter F. In alphabetical order, they are: chiffchaff