城镇
chéngzhèn · HSK 6
town
🏙️ 城 = city wall + 镇 = town/garrison; together: cities and towns
城 originally meant a walled city; 镇 meant a military garrison post that grew into a market town. The compound now covers all urban settlements from big cities down to small towns.
城 — earth radical 土 + 成 (to complete)
Originally a semantic-phonetic compound: 土 (earth) gives the meaning, since ancient cities were defended by rammed-earth walls, while 成 supplies the sound. The earliest meaning was 'city wall,' which later broadened to 'walled city' and then simply 'city' or 'town.'
镇 — metal radical 钅 + 真 zhēn (true)
A semantic-phonetic compound: 钅 (metal) gives the meaning, while 真 supplies the sound. Originally referred to a heavy metal object used to press or weigh something down, then extended to 'suppress, pacify, garrison.' Today it also means 'town,' from the idea of a fortified military post.