cisplatinPronunciation: /sɪsˈplatɪn/Definition of cisplatin noun [mass noun] Medicine a cytotoxic drug used in cancer chemotherapy. A coordination compound of platinum; chemical formula: Pt(NH3)2Cl2 Origin: late 20th century: from cis- (sense 2) + platinumcisplatin in other Oxford dictionaries Definition of cisplatin in the US English dictionary