clozapinePronunciation: /ˈkləʊzəpiːn/Definition of clozapine noun [mass noun] Medicine a sedative drug of the benzodiazepine group, used to treat schizophrenia. Origin: mid 20th century: from c(h)lo(ro)- + elements of benzodiazepineclozapine in other Oxford dictionaries Definition of clozapine in the US English dictionary