IPA: /ˌbaɪˈmɛtəlɪzəm/
KK: /ˌbaɪˈmɛtəlɪzəm/
A system where two metals, usually gold and silver, are used together as money, with a fixed value ratio between them.
Bimetallism was once a popular monetary system in many countries.
Bimetallism is formed from "bi-" (meaning two) and "metallum" (from Latin, meaning metal) and "-ism" (a suffix used to denote a practice or system). The term refers to a monetary system that uses two metals, typically gold and silver, as the basis for currency.
Think of 'two' ('bi-') types of 'metal' ('metallum') being used in a monetary system — that's what bimetallism means.