This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
The exact historical development of 圤 is uncertain. It visually combines 土 (earth) and 卜 (divination), but the original meaning and component relationship are unclear.
The kanji combines 土 (earth) and 卜 (divination). Picture a clod of earth used in an ancient divination ritual, but remember that its actual meaning is uncertain.
For ハク, imagine a diviner throwing a clod of earth onto a hakama (袴) during a ritual: hak -> ハク, and the earth clod lands with a soft thud.