low, humble
彽 centers on a low or humble state, describing something that is physically low or a person who is modest and unassuming.
彽 combines 彳 (a step or movement) with 氐, which likely contributes the sound and the idea of being low or base. The exact historical development is uncertain.
The left side 彳 suggests a person stepping or moving, and the right side 氐 looks like someone bowing low. Picture a humble person stepping forward with a low bow.
For チ, imagine a humble person bowing so low that their chin touches the ground: chin -> チ, and the low bow shows humility.