What does Nadia mean?
A Slavic name derived from Russian/Bulgarian Nadezhda, from Old Slavic for 'hope' (Proto-Slavic root naděja). Originally a diminutive of Nadezhda, it is widely used as a given name in its own right. Note: a separate Arabic name Nadiyyah ('tender, delicate') is sometimes conflated with it but is an unrelated root.
What does Danica mean?
A South Slavic name meaning 'morning star', the personification of the planet Venus at dawn in Slavic folklore. The root is debated between a word for 'day/dawn' and related forms, but the 'morning star' sense is consistent across sources.