免
miǎn · HSK 7
duty-free
✈️ 免 = exempt; duty-free is tax you are exempt from, also you are not allowed
Core sense of 免 is exempt or spare. Duty-free goods are exempt from tax, and the be not allowed sense comes from sparing or letting someone off a duty. Sound hook: miǎn rhymes with the start of mean.
免 — pictograph of a person 人 with a hat or helmet
免 originally depicted a person wearing a hat or helmet, suggesting removal or taking off. The meaning shifted to 'avoid, exempt, escape from' — as in escaping a duty or being spared. It is graphically related to 兔 (rabbit), but the two characters have distinct origins.