为止
wéi zhǐ · HSK 5
until
🛑 为 (wéi) = to be + 止 (zhǐ) = stop → 'be stopped' = until
止 (zhǐ) means 'stop' and shows up in 停止 (tíngzhǐ, halt) and 禁止 (jìnzhǐ, forbid). 到...为止 literally reads 'reaching ... it stops' — marking the cutoff point where something ends.
为 — simplified form of 為; from 爪 (claw/hand) over 象 (elephant)
The traditional form 為 originally depicted a hand leading an elephant, suggesting the act of doing or making work. Over time it generalized to mean 'to do, to act, for the sake of.' The simplified 为 preserves this 'do/for' meaning, with pronunciation shifting between wéi ('to be, to do') and wèi ('for, because of').
止 — pictograph of a foot/toe
止 originally depicted a human foot with toes, shown as a footprint on the ground. From this concrete image of a foot it came to mean 'to stop' or 'halt' — the place where a step ends. It also serves as a component in many characters relating to feet, walking, or stopping, such as 步 and 正.