This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
湈 combines 氵 (water) with 某, which likely contributes the sound. The exact historical development is uncertain.
Water 氵 beside 某 suggests a possible connection to water or a name, but the meaning is unclear.
For バイ, imagine buying a mysterious water-related item: buy -> バイ, and the water radical 氵 hints at its nature.