| follow the crowd | | | |
| follow the money | | | |
| follow through | | | |
| follow to the grave | | | |
| food baby | | | |
| food chain | | | |
| food for thought | | | |
| food noise | | | |
| fool around | | | |
| fool away | | | |
| fool's bargain | | | |
| fool's errand | | | |
| fool's paradise | | | |
| footgun | | | |
| foot-in-mouth disease | | | |
| foot the bill | | | |
| foot voting | | | |
| for a change | | | |
| for a fact | | | |
| for all one is worth | | | |
| for all the world | | | |
| for all the world to see | | | |
| for a song | | | |
| for beans | | | |
| forbidden fruit | | | |
| force down someone's throat | | | |
| force of habit | | | |
| force someone's hand | | | |
| for chrissake | | | |
| for crying out loud | | | |
| for dear life | | | |
| for England | | | |
| forever and a day | | | |
| for fear of | | | |
| for fear that | | | |
| for fucking out loud | | | |
| for fuck's sake | | | |
| for fudge's sake | | | |
| forget oneself | | | |
| forget to take one's medication this morning | | | |
| forget you | | | |
| forgive and forget | | | |
| forgive but don't forget | | | |
| for good | | | |
| for good and all | | | |
| for good measure | | | |
| for goodness' sake | | | |
| for goodness' sakes | | | |
| for grins | | | |
| for heaven's sake | | | |
| forked tongue | | | |
| for keeps | | | |
| fork off | | | |
| fork over | | | |
| for mercy's sake | | | |
| for my money | | | |
| for old times' sake | | | |
| for once | | | |
| for one's life | | | |
| for one's particular | | | |
| for one thing | | | |
| for Pete's sake | | | |
| for pity's sake | | | |
| for real and for true | | | |
| for reasons | | | |
| for shits and giggles | | | |
| for shits and grins | | | |
| for show | | | |
| for that matter | | | |
| for the ages | | | |
| for the asking | | | |
| for the birds | | | |
| for the book | | | |
| for the chop | | | |
| for the fuck of it | | | |
| for the hell of it | | | |
| for the love of | | | |
| for the love of me | | | |
| for the love of the game | | | |
| for the most part | | | |
| for the nonce | | | |
| for the plot | | | |
| for the time being | | | |
| for this once | | | |
| Fort Knox | | | |
| for toffee | | | |
| for two pins | | | |
| forty minutes of hell | | | |
| forty winks | | | |
| forward-leaning | | | |
| for XYZ reasons | | | |
| fossilized | | | |
| foul up | | | |
| fountain of youth | | | |
| four-eyes | | | |
| Four Horsemen of the Apocalypse | | | |
| four-leaf clover | | | |
| four-minute warning | | | |
| four-on-the-floor | | | |
| fourscore | | | |