Blouses were rarely part of the fashionable woman's wardrobe until the 1890s. Before that time, they were occasionally popular for informal wear in styles that echoed peasant or traditional clothing, such as the Garibaldi shirt of the 1860s.
Halterneck is a style of women's clothing with a single strap around the back of the neck. This can refer to either a dress or a separate shirt, called a halter top. The latter is a type of sleeveless shirt similar to a tank top (by the American English definition). The term "halter" comes from the German word for "holder", as in Büstenhalter, which literally means "busts-holder" and is equivalent to "brassiere".