Black-tie event

Black tie, occasionally known in the English-speaking world by its French name cravate noire, is a dress code for evening events and social functions derived from British and American costume conventions of the 19th century. For gentlemen, the principal elements of Black Tie are a white dress shirt with a black bow tie, an evening waistcoat or cummerbund and a dinner jacket (called a tuxedo in the United States).

Traditionally worn only for events after 7 p.m., black tie is less formal than white tie but more formal than informal or business dress. In the United States, the gentlemen's form of black tie attire is often referred to as a tuxedo.

For men, the elements of black tie are:

Women's dress for black tie occasions has varied greatly through the years; traditionally it was:

Today ladies dress for black tie occasions covers a much wider level of formality ranging from just below the white tie standard to something more informal such as a little black dress. Specifically it can also include:

Unlike the gentleman's standard, the specifics of black tie for ladies is linked to whatever evening wear is currently in fashion.

When the dinner jacket (tuxedo in American English) first came into fashion in the Victorian era, it was used as a less formal alternative for the tailcoat which men of the upper classes wore every evening. Thus it was worn with the standard accompaniments for the evening tailcoat at the time: matching trousers, white or black waistcoat, white bow tie, white detachable wing-collar formal shirt and black formal shoes. Lapels were often faced or edged in silk or satin in varying widths. Dinner jackets were considered from the first less formal than full dress (cutaway) and etiquette guides declared it inappropriate for wear in mixed company.

During the Edwardian era, the practice of wearing a black waistcoat and black bow tie with a dinner jacket became the convention, establishing the basis of the current black tie and white tie dress codes. The dinner jacket was also increasingly accepted at less formal evening occasions such as warm-weather gatherings or intimate dinners with friends.

...
Wikipedia