Gagarin, Yury Syllabification: (Ga·ga·rin, Yury)Pronunciation: /gəˈgärin/Definition of Gagarin, Yury (1934–68), Russian cosmonaut; full name Yury Alekseyevich Gagarin. In 1961, he made the first manned space flight, completing a single orbit of the earth in 108 minutes.
