thiramPronunciation: /ˈθʌɪram/Definition of thiram noun [mass noun] Chemistry a synthetic sulphur-containing compound used as a fungicide and seed protectant. Chemical formula: (CH3)2NCSS2SCN(CH3)2 Origin: 1950s: from thio-, (u)r(ea), and am(ine), elements of the systematic namethiram in other Oxford dictionaries Definition of thiram in the US English dictionary