This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
The exact historical development is uncertain. The modern form combines 糸 (thread) and 白 (white), but the original meaning and component function are unclear.
With no clear meaning, picture white thread (糸 + 白) wrapped around something, perhaps suggesting wrapping or binding, but treat this as a visual guess only.
For バツ, imagine a bat (バツ) made of white thread: the bat shape cues バツ while the thread component ties it to the kanji.