制約
せいやく · seiyaku · JLPT N1 · noun
restriction
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.