This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
蜲 combines 虫 (insect) with 委, which likely contributes the sound. The exact historical development is uncertain.
With 虫 on the left, 蜲 likely relates to an insect or worm. The right side 委 suggests a bending or twisting shape, like a wriggling creature.
For イ, imagine an insect wriggling and making a tiny 'ee' sound: ee -> イ.