Ga•ga•rin(gä gär′in, gə-; Russ. gu gä′ryin),USA pronunciationn.Yu•ri A•le•kse•ye•vich(yŏŏr′ē al′ik sā′ə vich; Russ. yo̅o̅′ryi u lyi ksye′yi vyich),USA pronunciation 1934–68, Russian astronaut: first human being to make an orbital space flight (1961).