[fly] {adj.} Quick witted, clever.

[fly-by-night] (1) {adj.} Set up to make a lot of money […]

[flying high] {adj.}, {slang} Very happy; joyful. * /Jack was flying […]

[foolproof] {adj.} So constructed that not even a fool can spoil […]

[footloose and fancy-free] {adj. phr.} Free and free to do what […]

[for free] {adj. phr.}, {substandard} Without having to pay; free. * […]

[for real] (1) {adj. phr.}, {informal} Not practice or play; earnest, […]

[for the best] {adj.} or {adv. phr.} good or best; not […]

[for the better] {adj.} or {adv. phr.} With a better result; […]

[for the birds] {adj. phr.}, {slang} Not interesting; dull; silly; foolish; […]