The Bulgarian name "Rosa" (meaning "dew" as a noun in Bulgarian) is pronounced rosa with a stress on the "a", i.e. with the sound "s", not "z" and a stress on the "a". Another Bulgarian name "Roza" (the stress is on the "o") means "rose" as a noun in Bulgarian, so the English names "Rose" and "Rosa" are equivalent to the Bulgarian "Roza".