handful
蕝 centers on a small amount grasped in one hand: a handful. Its meaning is narrow and concrete.
蕝 combines the grass radical 艹 with 絕, which likely contributes sound. The exact historical development is uncertain, and the character is rare.
The top 艹 suggests plant material, and the bottom 絕 looks like a tangled bundle. Imagine gathering a tangled handful of grass or herbs.
For セツ, picture a set of herbs tied in a handful: set -> セツ, and the bundle is just one handful.
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