The term 'UPSIDE-DOWN V' is a mathematical symbol known as the Lambda, which is represented by the Greek letter Λ. It is used in many areas of mathematics, including calculus and linear algebra. In computer science, it is often used to represent an anonymous function or a lambda expression. In physics, it is used to represent the wavelength of a wave. In chemistry, it is used to represent the bond angle of a molecule. In biology, it is used to represent the shape of a protein.