Nominal

Nominal generally derives from name. A nominal quantity (e.g., length, diameter, volume, voltage, value) is generally the quantity according to which some item has been named or is generally referred to. Such a nominal value may have no real relation to the item being referred to. For example, a type of battery that has an actual voltage of 1.62 V – but is commonly called a "1.5 volt battery" – has a nominal voltage of 1.5 V (which cannot be measured anywhere).