Gresh·am's law 
(grĕshəmz)
(grĕshəmz)n.
The theory holding that if two kinds of money in circulation have the same denominational value but different intrinsic values, the money with higher intrinsic value will be hoarded and eventually driven out of circulation by the money with lesser intrinsic value.
[After Sir Thomas Gresham.]
- fountain pen
- four
- four-bagger
- four-by-four
- fourchette
- four-color
- Four Corners
- four-cycle
- four-dimensional
- four-eyed
- four eyes
- four flush
- four-flush
- four-flusher
- four-footed
- fourgon
- fourhanded
- Four-H Club
- Four Horsemen of the Apocalypse
- Four Hundred
- Fourier
- Fourier analysis
- Fourierism
- Fourierist
- Fourierite