This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
徫 combines 彳 (movement) with 韋 (leather, surround). The exact historical development is uncertain, and the character is rare.
With no clear meaning, focus on the shape: a person walking (彳) beside a leather enclosure (韋).
For イ, imagine a person walking (彳) into a leather (韋) tent, saying 'Ee!' in surprise: 'Ee' -> イ.