To masticate means to chew your food. When you masticate, you're using your teeth and jaw to grind and break down food into smaller pieces that are easier to swallow and digest. Your molars, those flat teeth in the back of your mouth, are specially designed for mastication.

Scientists and doctors often use this formal word instead of “chew” when they're being precise about the process. A dentist might ask if you have any trouble masticating, or a biology teacher might explain how different animals masticate in different ways. Cows masticate their food twice, chewing it once, swallowing it, then bringing it back up to chew again. Humans masticate food just once before swallowing.

Your parents might have told you to chew your food thoroughly before swallowing. That's mastication in action. The more you masticate, the easier your stomach's job becomes. Some foods, like a tough piece of steak, require serious mastication. Others, like yogurt or smoothies, need almost none at all.