根底
こんてい · kontei · JLPT N1 · noun
basis
🌱 根 (root) + 底 (bottom) = the root at the bottom, the foundation
根 means root and 底 means bottom or base. Together they name the basis that everything else rests on.
根 — tree radical 木 + 艮 (phonetic)
根 is a semantic-phonetic compound. The left side 木 ('tree') gives the meaning, since the character originally referred to the roots of a tree. The right side 艮 supplies the sound. From 'tree root' it extended to mean 'root, base, foundation' in general.
底 — 广 (shelter radical) + 氐 (phonetic 'dǐ')
底 is a semantic-phonetic compound. The 广 radical depicts a roofed structure or shelter, suggesting the bottom or base of a building. The component 氐 supplies the sound 'dǐ' and originally meant 'low' or 'base,' reinforcing the meaning. Together they convey 'bottom,' 'foundation,' or 'underneath.'