This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
The exact historical development of 韴 is uncertain. It visually combines 音 (sound) and 帀, but the original semantic or phonetic role of 帀 is unclear.
With 音 (sound) on the left and 帀 on the right, imagine a sound that is cut off or interrupted, like a voice breaking. This fits the idea of a voice faltering or a sound stopping abruptly.
For ソウ, picture a soulful singer whose voice suddenly cuts out: soul -> ソウ, and the sound 音 is interrupted by the right side 帀.