This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
湗 combines 氵 (water) with 封, but the exact historical development and original meaning are uncertain.
The water radical 氵 beside 封 suggests something related to water or mud, but the exact meaning is unclear.
For ホウ, imagine a deep mud hole (ふかいどろ) that you hope to avoid: hope -> ホウ, and you steer clear of the muddy water.