What does Shivansh mean?
A modern compound of Shiva and amsha (अंश, 'portion/part'), read as 'a part of Lord Shiva'. A contemporary devotional coinage rather than a classically attested name.
What does Advik mean?
A modern Sanskrit-derived name generally glossed as 'unique, one of a kind', linked to the idea of advitiya ('without a second, incomparable'). The further association with advaita ('non-duality') is thematic rather than a direct etymology.