Cocktail dresses are actually semi formal dress which can be worn in both sizes; long as well as short just above the knee. The length of cocktail dresses is if 2 inches above the ankle, it is known by name of tea length cocktail dresses and if it is touching the ankle, it is called ballerina dress. Evening gown is also a form of such ballerina cocktail dresses. In movies, you can easily take glance of such cocktail dresses on body of actresses. It really gives a good look with high heels and dark shade lipstick.