chlordiazepoxidePronunciation: /ˌklɔːdʌɪazɪˈpɒksʌɪd/Definition of chlordiazepoxide noun [mass noun] Medicine a tranquillizer of the benzodiazepine group, used chiefly to treat anxiety and alcoholism. Also called Librium ( trademark).Origin: 1960s: from chlor- + diazo + epoxidechlordiazepoxide in other Oxford dictionaries Definition of chlordiazepoxide in the US English dictionary