軽率
けいそつ · keisotsu · JLPT N1 · na-adj
careless
🪶 軽 = light (weight) + 率 = rate: weighing things too lightly, so hasty and careless
軽 means light in weight, and 率 means rate or proportion. Giving too little weight to consequences before acting makes you thoughtless and hasty.
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.