imperial
Explains measurement system difference clearly
The unit of measurement from the british empire the "US unit" was based on. Very similar but with some differences. The pint, and therefore the gallon, is smaller in US than imperial units.
America took the british imperial unit, made the pint smaller because they can't handle their drink and called it "american" so that using any other standard of measurement would be unpatriotic.
Also in the dictionary
- imperial in industrial printing