noun: (pharmacology, uncountable) A platinum-containing antineoplastic drug cis-diamminedichloro-platinum(II) (Cl₂H₆N₂Pt) that is cytotoxic and is used especially in the treatment of testicular and ovarian tumors and advanced bladder cancer.
noun: (dated, countable) A platin, that is, a platinum-based antineoplastic, of which class cisplatin is the archetypal member.