This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
緺 combines 糸 (thread) with 咼, which likely contributes a phonetic element. The exact historical development is uncertain.
With 糸 (thread) on the left and 咼 on the right, picture a tangled thread wrapped around a mysterious object, its meaning uncertain.
For カイ, imagine a kite (カイト) tangled in the thread: kite -> カイ, and the thread wraps around the kite.
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