This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
The exact historical development of 肁 is uncertain. It visually combines 户 and 聿, but the original semantic and phonetic roles are unclear.
With no clear meaning, picture a door (户) with a brush (聿) stuck inside—an odd, memorable image for a rare kanji.
For チョウ, imagine a long-serving chief named Chou trying to open the door (户) with a brush (聿): Chou -> チョウ.