equal
匀 centers on the idea of equal distribution or balance, making things even or uniform.
匀 is the simplified form of 勻. The older form 勻 combines 勹 (wrap) with 二 (two), suggesting dividing something into two equal parts, hence 'equal'.
The outer 勹 wraps around the inner 冫 (two drops), like dividing a wrapped package into two equal portions.
For イン, imagine an innkeeper dividing rooms equally among guests: inn -> イン, and the innkeeper ensures everything is equal.