This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
The exact historical development is uncertain. The character combines 氵 (water) with 鬵, but the original semantic and phonetic roles are unclear.
With no clear meaning, focus on the shape: water 氵 beside the dense component 鬵. Remember it as a rare water-related kanji whose meaning is unknown.
For セン, imagine a mysterious water spirit named Sen rising from the 氵 side of 灊: Sen -> セン, and the unknown kanji is its name.
—