秩序
zhìxù · HSK 7
order
🔢 秩 (rank) + 序 (sequence) = two order-words doubled up for emphasis
Both characters already mean order on their own, so 秩序 stacks synonyms — a common Chinese pattern where pairing two near-identical words reinforces the sense. 序 also shows up in 顺序 (sequence) and 序言 (preface, the part that comes first in order).
序 — 广 radical (shelter) + 予 (give/I)
Originally depicted the side walls or wings of a building under the 广 (shelter) radical, with 予 serving as the phonetic component. From 'side wall' it extended to mean 'sequence' or 'order,' as walls were arranged in succession. Today it commonly means 'order,' 'sequence,' or 'preface.'