Rousseau, Théodore Syllabification: (Rous·seau, Théodore)Pronunciation: /ro͞oˈsō/Definition of Rousseau, Théodore (1812–67), French painter; full name Pierre Étienne Théodore Rousseau. A leading landscapist of the Barbizon School, his works typically depict the scenery and changing light effects of the forest of Fontainebleau. Rousseau, Théodore in other Oxford dictionaries Definition of Rousseau, Théodore in the British & World English dictionary