Dewey, John Syllabification: (Dew·ey, John)Pronunciation: /ˈd(y)o͞o-ē/Definition of Dewey, John (1859–1952), US philosopher and educational theorist. He defined knowledge as successful practice and espoused the educational theory that children learn best by doing. Dewey, John in other Oxford dictionaries Definition of Dewey, John in the British & World English dictionary