This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
隥 combines ⻖ (hill, mound) with 登 (ascend). The structure suggests ascending a hill or slope, but the exact historical development is uncertain.
The left side ⻖ suggests a hill or slope, and the right side 登 means to climb or ascend. Picture a steep hill that must be climbed, though the kanji's meaning is unclear.
For トウ, imagine climbing a tall hill: tall -> トウ, and the hill is steep like the ⻖ on the left.