Nonsmoking describes a place where smoking cigarettes, cigars, or pipes is not allowed. A nonsmoking restaurant means you can't light up a cigarette at your table. A nonsmoking hotel room means previous guests weren't allowed to smoke there, so it won't smell like stale smoke when you check in.

Today, most public buildings in America are entirely nonsmoking because secondhand smoke (smoke that drifts from someone else's cigarette) can harm people's health. Airlines, which once let passengers smoke during flights, became nonsmoking decades ago.