"Knee-high" refers to a measurement that indicates something reaches up to the height of a person's knee. This term is often used to describe the length of clothing, such as skirts or pants, as well as the height of grass or plants. It provides a visual reference for size and scale in various contexts. In agriculture, "knee-high" is commonly used to assess the growth of corn during the early summer months. Farmers often say that corn should be "knee-high by the Fourth of July," which serves as a guideline for healthy crop development. This phrase highlights the importance of growth stages in farming practices.