The word udanvān is irregularly formed in the sense of 'a sea'.,
It is derived from उदक 'water' with the affix मत् ॥ उदन्वान् is the name of a Rishi, because he controlled the rains, it rained at his command. It also means occan or that in which water is held, like तटाक &c. The affix कि is added by 3.3.93, and उदक changed to उद् by 6.3.58, and thus we have उदधिः ॥ Why do we say \when meaning a sea\? Observe उदकवान् घटः 'a pot having water'. Here the main idea is not that of \holding or containing\, but simply the general fact of possessing water: a human being may also possess water in the same way.,