正当
せいとう · seitou · JLPT N1 · na-adj
proper
⚖️ 正 = correct + 当 = fitting or applicable, so 正当 means proper, just, or legitimate
Pronounced seitou. The first character 正 means correct or right, and the second 当 means fitting or applicable. Together they describe what is rightly due or justified.
正 — one 一 + stop 止
Originally an ideograph showing a foot (止) advancing toward a target line (一), meaning 'to march straight toward' a city or goal. From this came the senses 'upright,' 'correct,' and 'proper.' The military sense survives in 征 (to campaign), which took over the original 'march' meaning.
当 — small ⺌ + crown 冖 + hand 彐 (simplified from 當: 尚 + 田)
Originally written 當, combining 田 'field' with 尚 as a phonetic. The early sense was 'to match' or 'face' a field of equal value, extended to 'correspond to', 'ought to', and 'serve as'. The simplified form 当 streamlines the upper 尚 component.