stump, foolish, ignorant
檮 centers on a tree stump, which is the leftover base of a cut tree. The meanings 'foolish' and 'ignorant' likely extend from the idea of something dull, inert, or lacking growth, like a stump compared to a living tree.
檮 combines 木 (tree) with 壽, which likely contributes the sound. The character originally referred to a tree stump or a type of tree, and the extended meanings of foolishness or ignorance may derive from the idea of a stump being dull or unproductive.
A tree 木 beside 壽, which looks like an old, gnarled shape. Picture an ancient, withered tree stump—useless and ignorant of the world around it.
For トウ, imagine a toe stubbing against a stubborn tree stump: toe -> トウ, and the pain reminds you of the foolish stump.
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