to bump
朾 centers on striking or bumping into something, as the single given meaning suggests. It is a rare character with a narrow physical action sense.
朾 combines 木 (tree/wood) with 丁, which likely contributes the sound. The exact historical development is uncertain, but the structure suggests a phono-semantic compound where 木 hints at a wooden object used for bumping or striking.
A wooden (木) nail (丁) is hammered, causing it to bump against the surface. Imagine the sound of wood striking wood.
For トウ, picture bumping your toe (トウ) against a wooden post: toe -> トウ, and the impact makes you hop.