An evening gown is a long, flowing lady'sdress usually worn to a formal affair. It ranges in length from tea and ballerina to full-length. Gowns are often made of a luxury fabric such as chiffon, velvet, satin, or silk.
A gown for a black tie event may be full length, ballet, or tea (mid-calf to ankle) length. In general, the same rules as a white-tie event apply to a black-tie event, though in some cases a cocktail dress may be acceptable.
To accompany a gentleman wearing a formal kilt, a lady wears a white gown with a tartan sash. A less formal variant is a longer kilted skirt with jacket. The sash or kilted skirt may be the tartan of the woman's own clan (if she is entitled to wear one), of her husband's clan, or any of the "district tartans" approved for general wear.
Alternatives to the gown
In the 1940s, couturiers introduced dancing costumes, a party dress with a full skirt specifically made for semi-formal and formal dances. The dancing costume was shorter than the evening gown.
A ball skirt is a variant fashion which resurfaced in the 1990s, consisting of a full, long skirt that can be worn with a cashmere sweater, lace camisole, or other dressy top.