noun
fractional currency; subsidiary coinage
Economic term for small-denomination money used alongside the main currency unit, such as cents or pence.
補助通貨として、1セント硬貨や5セント硬貨が発行されている。
As fractional currency, 1-cent and 5-cent coins are issued.
この国では補助通貨の単位としてセントが使われている。
In this country, cents are used as the unit of fractional currency.
本位通貨 is the standard monetary unit (e.g., dollar, yen), while 補助通貨 refers to the smaller fractional units.
Compound of 補助 (ほじょ, 'auxiliary, supplementary') and 通貨 (つうか, 'currency'). The term is a direct calque from Western economic terminology.