This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
The exact historical development of 衟 is uncertain. It visually contains 行 (going, road) as an outer enclosure, but the inner component's origin is unclear.
The outer shape 行 suggests a road or path, but the inner part is obscure. Imagine a forgotten path marker with a worn-away center, its meaning lost to time.
For トウ, picture a faded road sign pointing to a distant tower: tower -> トウ, and the path 行 leads there.