海关
hǎiguān · HSK 3
custom
🛃 海关 = sea + pass/gate; the gate at the sea where goods are checked
海 means sea and 关 means pass, gate, or barrier. Historically, customs offices sat at coastal ports where ships entered, so the compound literally names the gate-at-the-sea that inspects incoming cargo.
海 — water radical 氵 + 每 (phonetic)
海 is a phono-semantic compound. The 氵 (water) radical signals the meaning—a vast body of water—while 每 supplies the sound. Originally referring to the sea or ocean, it later extended figuratively to mean 'vast' or 'a great quantity,' as in 人海 (a sea of people).
关 — door 门 + simplified 关 inside
关 is the simplified form of 關. The traditional character showed a gate (門) with a bolt or crossbar inside, depicting a barred door — hence 'to close' or 'shut'. Meaning later extended to 'pass' (a guarded gate), 'barrier', and figuratively 'concern' or 'connection'.