Unsanitary means not clean or healthy, in a way that could spread germs and make people sick. An unsanitary bathroom has dirty toilets, grimy sinks, and trash overflowing onto the floor. An unsanitary kitchen might have moldy food sitting out, cockroaches crawling on counters, or crusty dishes piled in the sink for weeks.

Think of sanitary conditions as those that protect health: clean water, proper waste disposal, and surfaces free from harmful bacteria. Unsanitary conditions do the opposite, creating environments where disease can spread.

Hospitals work hard to avoid unsanitary conditions because sick patients can easily catch new infections. Restaurants can get closed down for unsanitary kitchens. In the 1800s, many cities had terribly unsanitary conditions, with garbage rotting in streets and sewage contaminating drinking water, which caused frequent outbreaks of cholera and other diseases. Public health improvements that created more sanitary cities saved millions of lives.

When you leave wet towels in a heap or forget lunch in your locker for a month, you're creating unsanitary conditions on a small scale. The word reminds us that cleanliness isn't just about appearances: it's about health and safety.