[fifth column] {n. phr.} A group or organization within a country […]

[fighting chance] {n. phr.} A chance that necessitates struggle and courage; […]

[filth (the)] {n.} The police (derogatory).

[filthy lucre] {n.}, {informal} Money, especially when thought of as bad […]

[fine-tooth comb] {n. phr.} Great care; careful attention so as not […]

[finger in the pie] also [finger in every pie] {n. phr.}, […]

[firebug] {n.} An arsonist; one who willfully sets fire to property. […]

[firing squad] {n.} A group of soldiers chosen to shoot a […]

[first base] {n. phr.} 1. The base that must be touched […]

[first class] {n.} 1. The first rank; the highest class; the […]