This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
圿 combines 土 (earth) with 介, but the exact historical development is uncertain. It may have originally related to dirt or dust, but this is speculative.
The left side is earth 土, and the right side 介 looks like a person between boundaries. Picture dirt or dust settling between cracks in the earth, but remember the meaning is uncertain.
For カツ, imagine cutting through dirt with a sharp tool: cut -> カツ, and the earth 土 is sliced by the 介 shape.