This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
裷 combines 衤 (clothing) with 卷, which likely contributes the sound. The exact historical development is uncertain.
The clothing radical 衤 beside 卷 suggests something related to garments, but the exact meaning is unclear.
For エン, imagine an ancient robe with a round collar: the round shape cues 円 (えん), and the robe is clothing 衤.