Ballgown refers to a type of long dress that is fitted at the bodice, with a very full skirt.. This is the most formal dress silhouette, usually reserved for the dressiest of occasions . The Ballgown looks best on average height to taller women, as the full skirt visually cuts the body in half. However, the Ballgown is a very forgiving style, hiding everything from tummies to full hips and legs.