The antonym for the word "nonvegetable" is "vegetable." A vegetable is any edible part of a plant, such as celery, spinach, broccoli, and carrots. These foods are typically low in calories, high in nutrients, and important for overall health. Vegetables provide fiber, vitamins, and minerals that are essential for digestion and the body's immune system. Eating a diet rich in vegetables can help prevent chronic diseases, such as heart disease, diabetes, and some cancers. So if you want to maintain a healthy lifestyle, it's important to incorporate more vegetables into your diet and reduce your intake of nonvegetable foods.