The initial idioms of the letter F

fouled up	foul
foul-mouthed	found money
found on	foundation
found	foundry
fountain of youth	four
four corners of the earth, the	Four Horsemen of the Apocalypse
four score and seven years ago	four sheets
four sheets in the wind	four sheets to the wind
four wheels	four-bagger
four-bits	four-eyes
four-flusher	four-leaf clover
four-oh-four	four-one-one
fourth	the Fourth Estate
fourth wall	four-topper
fowl	fox's sleep