edge, margin, side, border
邉 centers on the outer limit or boundary of something: an edge, margin, side, or border.
邉 is a variant form of 邊. The traditional form 邊 combines 辶 (movement) with 臱 (which likely contributed the sound), expressing the idea of a boundary or edge. The modern simplified form is 辺.
The outer 辶 suggests a path or movement, while the inner block (自 over 穴 over 口) looks like a nose (自) peering into a cave (穴) with an opening (口). Picture walking along a path and reaching the edge where a nose pokes out of a cave mouth—that's the border.
For ヘン, imagine a hen standing at the edge of a path, pecking at the border: hen -> ヘン.