quinidinePronunciation: /ˈkwɪnɪdiːn/Definition of quinidine noun [mass noun] Medicine a compound obtained from cinchona bark and used to treat irregularities of heart rhythm. It is an isomer of quinine. Origin: mid 19th century: from Spanish quina 'cinchona bark' (from Quechua kina 'bark') + -ide + -ine4quinidine in other Oxford dictionaries Definition of quinidine in the US English dictionary
