底子
dǐ zi · HSK 7
base
🧱 底 (bottom) + 子 (suffix) = the底子base everything rests on
底 means bottom or underside. Adding 子 turns it into a noun: the foundational layer beneath something. Think of the底子of a shoe — the sole that supports every step.
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.'
子 — pictograph of a baby/child with arms out
子 began as a pictograph of a swaddled infant with a large head and outstretched arms, originally meaning 'baby' or 'child.' From there it broadened to 'son,' 'offspring,' and a respectful suffix for masters like 孔子 (Confucius). It also became one of the twelve earthly branches.