Smoke-free describes a place where smoking is not allowed — a smoke-free restaurant, a smoke-free office, a smoke-free campus. It is an adjective, usually written with a hyphen before a noun, and it can also sit after the verb: "the whole building is smoke-free," "the city went smoke-free in 2009." Notice what the word really claims. It does not mean nobody happens to be smoking at the moment; it means there is a rule, and the rule is being announced. So a sign saying SMOKE-FREE ENVIRONMENT is a polite way of saying no smoking here — the positive wording makes it sound like a benefit rather than an order, which is exactly why public health campaigns chose it. That is worth noticing: the word was designed to sound welcoming. There is a second, less common use about people: a smoke-free life, or someone who is now smoke-free, meaning they have stopped smoking. That one is mostly heard in health advice and quit-smoking programmes. In Taiwan the word turns up in English signs at airports, hotels and hospitals, and matches 禁菸 on the Chinese side of the same sign.