边界
biānjiè · HSK 7
boundary
🚧 biān = side/edge + jiè = boundary — the edge-limit of a region
Each character pulls its weight: 边 (biān) means side or edge, jiè (界) means realm or boundary. Together they mark where one territory ends and another begins — the outer limit, the margin.
边 — 辶 (walk) + 臱 (phonetic)
边 is the simplified form of 邊. It combines the walking radical 辶 with the phonetic component 臱, suggesting a place reached by walking — the edge or border of a territory. The meaning extended from 'frontier' to 'side' or 'edge' in general.
界 — field 田 + scope 介
界 combines 田 (field) as the semantic component with 介 (jiè) as the phonetic. The original sense referred to boundaries between fields, then broadened to any border, limit, or realm — yielding modern meanings like 'world' (世界) and 'boundary' (边界).