I am not sure the meaning is correct. It is probably from the verb "to grow" which in Serbian is "rasti", I don't know the actual form in the other Slavic languages. Therefore the meaning is "to increase glory (of the bearer)".
Famous bearers: Hockey player Rostislav Klesla Actor Rostislav Kuba Hockey player Rostislav Malena Hockey player Rostislav Martynek Actor Rostislav Novák Hockey player Rostislav Olesz Historian/theorist Rostislav Švácha Hockey player Rostislav Vlach Footballer Rostislav Vojáček