[flare-up] {n.} The reoccurrence of an infection or an armed conflict. […]

[flash card] {n.} A card with numbers or words on it […]

[flash in the pan] {n. phr.}, {slang} A person or thing […]

[flasher] {n.} Someone who indecently exposes oneself.

[flatfoot] {n.}, {slang}, {derogatory} A policeman. * /"What does Joe do […]

[flea in one's ear] {n. phr.}, {informal} An idea or answer […]

[flea market] {n. phr.} A place where antiques, second-hand things, and […]

[flesh and blood] {n.} 1. A close relative (as a father, […]

[flick] {n.} Motion picture, film. 'The flicks', the cinema.

[flip-flop] (2) {n.}, {informal} A complete change; a switch from one […]