This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
莍 combines the grass radical 艹 with 求, but the exact historical development and original meaning are uncertain.
The top 艹 suggests a plant, and the bottom 求 looks like a person seeking something. Imagine a rare herb that people seek, but its true use is unknown.
For キュウ, imagine a curious person seeking the rare plant and asking 'Q?' (cue) — the sound 'Q' cues キュウ.
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