to go round, to make a circuit, to make a revolution, to turn round
帀 centers on circular motion: going around, making a circuit, revolving, or turning round. All given meanings are direct expressions of this single idea of encircling or rotating movement.
帀 is a rare character. It visually combines 一 (one) over 巾 (cloth), but the historical origin is uncertain. It may have originally depicted something encircling or wrapping, but the exact development is unclear.
Picture a cloth (巾) with a single line (一) above it, like a ribbon tied in a loop. The ribbon goes round and round, making a circuit.
For ソウ, imagine sewing a circular patch onto a cloth: sew -> ソウ, and the needle goes round and round.