This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
The exact historical development of 訄 is uncertain. It visually combines 九 and 言, but the original semantic or phonetic role of these components is unclear.
The kanji encloses 言 (words) inside 九 (nine). Without a clear meaning, picture nine tangled words trapped inside a box, representing something obscure or hard to define.
For キュウ, imagine nine (九, きゅう) words (言) shouting together: 九 -> キュウ, and the nine voices make a confusing noise.
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