Marrow refers to a type of squash that typically has a long, cylindrical shape and smooth, green skin. It is a variety of summer squash, similar to zucchini, and has a mild, slightly sweet flavor. Marrow can be harvested when young and tender or allowed to grow larger and develop a firmer texture. It is commonly used in cooking and can be grilled, roasted, sautéed, or stuffed. Marrow is versatile and can be incorporated into a variety of dishes, including soups, stews, casseroles, and salads. It is rich in vitamins, minerals, and dietary fiber, making it a nutritious addition to meals.