制限
せいげん · seigen · JLPT N3 · noun
restriction
🚧 制限 = control (制) + limit (限): a limit imposed by control
制 means control or system, as in 制度 (system), and 限 means limit, as in 限界 (boundary). When you control something and set a limit on it, you get a restriction. Speed limits are 速度制限, and age limits are 年齢制限.
制 — knife 刂 + 未 (tree branches)
Originally depicted a knife 刂 cutting branches from a tree, showing the act of trimming or shaping wood. From this concrete sense of cutting to size came the meanings 'to make,' 'to manufacture,' and by extension 'to control' or 'regulate' — shaping things to a desired form.
限 — mound radical 阝 + 艮 (phonetic)
限 combines the 阝 (mound/hill) radical on the left with 艮 on the right, which provides the sound. The mound element suggests a boundary or barrier formed by terrain, and the character came to mean 'limit' or 'boundary' — the edge one cannot cross.