Tobacco is a plant whose leaves contain a powerful drug called nicotine. For centuries, people have dried these leaves and smoked them in cigarettes, cigars, and pipes, or chewed them directly. When tobacco smoke enters the lungs, nicotine quickly reaches the brain and creates a temporary pleasant feeling, but it's also highly addictive, meaning people who start using it find it extremely hard to stop.

Tobacco's story is one of the strangest in history. Native Americans grew tobacco for thousands of years, and European explorers brought it back across the Atlantic in the 1500s. By the 1900s, cigarette smoking had become enormously popular worldwide. Companies sold cigarettes everywhere, and people smoked in offices, restaurants, and even airplanes.

Then scientists made a crucial discovery: smoking tobacco causes serious diseases, including lung cancer, heart disease, and emphysema. The evidence became overwhelming. Today we know that smoking is one of the most dangerous things a person can do to their health. Most countries now restrict where people can smoke and require warning labels on tobacco products.

The word can also describe the color of dried tobacco leaves: a warm, reddish-brown. You might see furniture or clothing described as tobacco brown.