one
弌 is an archaic variant of 一, meaning one. It represents the number one or a single unit.
弌 is an ancient variant form of 一, created by adding 弋 as a phonetic or distinguishing element. The exact historical development is uncertain, but it served as a formal or alternative way to write 'one'.
The outer shape 弋 looks like a stake, and the single inner stroke 一 marks it as one. Picture a single tally mark on a counting stick.
For イチ, imagine an itchy single mosquito bite: itchy -> イチ, and you count just one bite.