Etymology According to some, his name is derived from the Isle of Man with the suffix indicating 'one who is from' the named place. The island's name itself may come from a Celtic word for 'mountain' or 'rise', as the Isle of Man rises from the sea on the horizon.If the name of Man reflects the generic word for 'mountain', it is impossible to distinguish this from a generic 'he of the mountain'; but the patronymic , interpreted as 'son of the Sea', is taken to reinforce the association with the island. See, e.g.: Alternatively, it may come from an earlier Proto-Indo-European root for 'water' or 'wetness'. In medieval Irish tradition, it appears that Manannán came to be considered eponymous to the island (rather than vice versa)., invoking John Rhŷs.
etymology according to some his name is derived from the isle of man with the suffix indicating 'one who is from' the named place the island's name itself may come from a celtic word for 'mountain' or 'rise' as the isle of man rises from the sea on the horizonif the name of man reflects the generic word for 'mountain' it is impossible to distinguish this from a generic 'he of the mountain'; but the patronymic  interpreted as 'son of the sea' is taken to reinforce the association with the island see eg alternatively it may come from an earlier proto-indo-european root for 'water' or 'wetness' in medieval irish tradition it appears that manannán came to be considered eponymous to the island (rather than vice versa) invoking john rhŷs