"Hydrophobic" refers to the property of a substance that repels water. This means that hydrophobic materials do not mix well with water and tend to avoid it. Common examples of hydrophobic substances include oils and fats, which do not dissolve in water and often form separate layers when combined. In scientific terms, hydrophobicity is important in various fields, including biology and chemistry. For instance, the structure of cell membranes is largely hydrophobic, allowing cells to maintain their internal environment. Understanding hydrophobic interactions helps in the development of water-repellent coatings and drug delivery systems.