十足
shízú · HSK 5
100 percent
💯 十 (ten) + 足 (foot/sufficient) = ten parts full, i.e. 100%
十 means ten and 足 means foot or enough/sufficient; together literally ten-tenths-worth, so completely or downright. Same 足 appears in 满足 (satisfied) and 足够 (enough).
十 — single horizontal 一 + vertical 丨
十 originated as a simple vertical line in oracle bone script, representing the number ten, possibly from a knotted cord used for counting. Over time a horizontal stroke was added, giving the modern cross shape. It has consistently meant 'ten' or 'complete' throughout Chinese history.
足 — top 口 (mouth/enclosure) + bottom 止 (foot)
Originally a pictograph of a leg and foot, with the upper square representing the knee or shin and the lower part 止 depicting the foot itself. It primarily means 'foot' and by extension 'sufficient' or 'enough,' a meaning shift likely from the idea of standing firmly or having a solid footing.