у̀спјех (Serbo-Croatian) comes from Proto-Slavic spěxъ, from Proto-Slavic spěti, from Proto-Balto-Slavic spḗˀtei, from Proto-Indo-European spéh₁-, from Proto-Indo-European speh₁- — to succeed, to prosper.
у̀спјех (Serbo-Croatian): success