green sprout, foolish
芚 is a rare kanji with two seemingly unrelated meanings: a green sprout and foolishness. The connection is unclear, so treat it as having two distinct senses.
芚 combines the grass radical 艹 with 屯, which may have contributed sound. The exact historical development and the link between 'green sprout' and 'foolish' are uncertain.
Picture a foolish green sprout pushing up through the grass 艹, with the lower part 屯 looking like a tangled root that makes it grow in a silly direction.
For トン, imagine a ton of foolish green sprouts bursting from the ground: ton -> トン, and the sprouts are everywhere.
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