This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
The exact historical development is uncertain. The modern form visually contains 尉 over 虫, but the original component relationship is unclear.
The top component 尉 suggests a military officer, and the bottom 虫 is an insect. Imagine an officer inspecting a strange insect, but the meaning remains unclear.
For イ, picture an insect (虫) that makes a tiny 'ee' sound: 'ee' -> イ, though the kanji's meaning is uncertain.