軽率
けいそつ · keisotsu · JLPT N1 · na-adj
careless
率 — twisted silk threads with droplets, plus 十
率 originally pictured a net or twisted bundle of silk cords with water droplets shaking off, suggesting something being led or pulled along. From 'leading a rope' it extended to 'lead, command' (shuài) and to 'rate, ratio' (lǜ), as in a fixed proportion. The two readings share this core image of a guiding measure.