Diaghilev, SergeiPronunciation: /dɪˈagɪlɛf/Definition of Diaghilev, Sergei (1872–1929), Russian ballet impresario; full name Sergei Pavlovich Diaghilev. In 1909 he formed the Ballets Russes, which he directed until his death. Diaghilev, Sergei in other Oxford dictionaries Definition of Diaghilev, Sergei in the US English dictionary