This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
渞 combines the water radical 氵 with 首, but the exact historical development and original meaning are uncertain.
Water 氵 beside a head 首: imagine a head emerging from water, but the meaning remains unclear.
For シュ, picture a shoe floating on the water next to the head: shoe -> シュ, though the scene is as mysterious as the kanji's meaning.