This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
The exact historical development of 畗 is uncertain. It may be a variant or simplified form, but its origin is not well documented.
With no clear meaning, picture a mysterious container: 亠 is the lid, 口 is the opening, and 田 is the base. Something unknown fills it.
For トウ, imagine a tall tower (タワー -> トウ) shaped like 畗, with the lid 亠 on top, the opening 口 in the middle, and the base 田 at the bottom.