What does Varuna mean?
In Vedic Hinduism Varuna is the deity of the waters, oceans, rivers and the celestial waters. The name is Sanskrit; later tradition firmly associates him with the sea and all water.
What does Nagendra mean?
Sanskrit compound of naga 'serpent' + Indra (as the suffix -endra 'lord, chief'), read as 'lord/king of serpents'. Hedge: the naga element is secure, and this split is the standard reading, but I could not confirm the full compound against a Sanskrit lexicon rather than name-reference sites, so treat the exact gloss as the common interpretation.