封锁
fēng suǒ · HSK 7
to blockade
🚧🔒 封 = seal/envelope + 锁 = lock; together: seal and lock shut
封 means to seal or close (think envelope-sealing) and 锁 means a lock. A blockade seals off a place and locks it down. 封 also appears in 封闭 (closed off) and 信封 (envelope); 锁 in 锁门 (lock the door).
封 — earth 土 doubled (圭) + inch 寸 (hand)
Originally a pictograph of a hand planting a sapling on a mound of earth, marking a boundary. From this came the meaning of granting fiefs to nobles, then sealing or closing off territory. The modern senses 'to seal' and 'envelope' both stem from this idea of enclosing.
锁 — metal radical 钅 + 𫔑 (small/phonetic)
锁 means 'lock' or 'chain.' The metal radical 钅 (金) signals a metal object, while the right side originally depicted small linked rings, hinting at both meaning and sound. Early locks were chains of small metal pieces, so the character paints a picture of linked metal.