What does Avni mean?
From the Sanskrit अवनि (avani), 'the earth, ground, a river-bed'. A genuine Vedic/classical word for the earth.
What does Advika mean?
A recent given name derived from Sanskrit advitiya / advaita, 'unique, matchless, without a second'. The root is genuine Sanskrit, but the name itself is a modern coinage, appearing in records only in the 2000s.