This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
袘 combines the clothing radical 衤 with the phonetic component 㐌, suggesting a garment-related word. The exact historical development is uncertain.
The clothing radical 衤 suggests a garment, but the overall meaning is obscure. Picture a mysterious robe with an unknown name.
For イ, imagine an 'e' (as in the letter E) embroidered on the robe: 'e' -> イ, a simple sound hook for this rare kanji.