in
Fill (something) in
Fill in the blanks
Fill out (something)
Fill the bill
Filled to the brim
Find (someone) guilty
Find (someone) innocent
Find fault with (someone or something)
Find it in one's heart to (do something)
Find Mr. Right
Find one's feet
Find one's own level
Find one's tongue
Find one's way
Find oneself
Find out (something)
Fine and dandy
Fine how-do-you-do
Fine kettle of fish
Fine state of affairs
Fine-tooth/toothed comb
Fine-toothed/tooth comb
Finger in the pie
Fire a gun
Fire away at (someone or something)
Firing on all cylinders
Firm hand
First and foremost
First come, first served
First hand
First love
First of all
First off
First out of the gate
First past the post
First things first
First-run
Firsthand
Fish for (something)
Fish for a compliment
Fish in troubled waters
Fish or cut bait
Fish out of water
Fishy
Fit (someone or something) in
Fit (someone) into a schedule
Fit (someone) out with (something)
Fit (someone) to a T
Fit and trim
Fit as a fiddle
Fit for a king
Fit in with (someone or something)
Fit like a glove
Fit the mold
Fit to be tied
Fit to kill
Fix (someone's) wagon
Fix (someone) up with (someone)
Fizzle out
Flare up
Flash in the pan
Flat broke
Flat out
Flea in (someone's) ear
Flea market
Flesh (something) out
Flex one's muscles
Flight of fancy
Flip one's lid
Flip out
Flirt with the idea of (doing something)
Float (someone) a loan
Float a loan
Flog/beat a dead horse
Flora and fauna
Flunk out
Flush with (something)
Fly by the seat of one's pants
Fly in the face of (something)
Fly in the ointment
Fly into the face of danger
Fly off the handle
Fly the coop
Fly-by-night
Flying high
FM
Foam at the mouth
Foist (something) off on (someone)
Fold (something) up
Fold one's hands
Follow (someone's) lead
Follow in (someone's) footsteps
Follow one's heart
Follow one's nose
Follow orders
Follow suit
Follow the crowd
Follow through on/with (something)
Follow up (something)
Fond of (someone or something)
Food for thought
Fool and his money are soon parted
Fool around
Foot in the door
Foot the bill
Footloose and fancy-free
For a song
For all (something)
For all I care
For all I know
For all intents and purposes
For all one is worth
For all practical purposes
For all the world
For better or worse
For
