A nonsmoker is a person who doesn't smoke cigarettes, cigars, pipes, or similar tobacco products. Some people are nonsmokers because they never started smoking, while others quit after smoking for years.

The word matters most in practical situations. Hotels often have nonsmoking rooms where smoking isn't allowed, keeping the air fresh for guests who don't want to smell tobacco smoke. Rental car companies advertise nonsmoker vehicles. Some apartment buildings are entirely nonsmoking to protect residents from secondhand smoke drifting between units.

When doctors ask if you're a nonsmoker, they're gathering important health information, since smoking affects lung capacity, heart health, and many other body systems. Life insurance companies often charge nonsmokers less because they typically face fewer health risks.

The term can feel a bit odd since it defines someone by what they don't do, like calling someone a “non-piano player.” But smoking became so common in the 1900s that the word became necessary to distinguish between people who smoke and those who don't, especially in contexts where tobacco smoke affects everyone nearby.