彻底
chèdǐ · HSK 4
thorough
🧹 彻底 = 彻 (penetrate through) + 底 (bottom) — going all the way to the bottom
彻 means to penetrate or pass through; 底 means bottom or base. Together: reaching the very bottom of something, i.e. doing it thoroughly, completely, exhaustively — no stone unturned, no half-measures.
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.'