butadienePronunciation: /ˌbjuːtəˈdʌɪiːn/Definition of butadiene noun [mass noun] Chemistry a colourless gaseous hydrocarbon made by catalytic dehydrogenation of butane. It is used in the manufacture of synthetic rubber. Chemical formula: CH2CHCHCH2 Origin: early 20th century: from butane + di-1 + -enebutadiene in other Oxford dictionaries Definition of butadiene in the US English dictionary