type of evergreen tree, (kokuji)
椥 is a Japanese kokuji for a specific type of evergreen tree, likely the nagi tree (Podocarpus nagi). Its meaning is narrow and botanical, without broader abstract extensions.
椥 is a Japanese kokuji, created by combining 木 (tree) with 知 (likely for its sound チ, though the reading is なぎ). The exact historical motivation is uncertain, but it was probably formed to represent the nagi tree.
A tree 木 that you might know 知 as an evergreen: 椥 is the nagi tree.
For なぎ, picture a calm (凪, なぎ) sea breeze rustling through the leaves of this evergreen tree: なぎ -> なぎ.
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