Jumper (dress)
A jumper dress or simply jumper (British English: pinafore dress, pinafore, pinny), is a sleeveless, collarless dress intended to be worn over a blouse or sweater. It may or may not have straps, like those found on overalls. There is sometimes confusion over the name, as in British English, a jumper is a woollen sweater.
A sundress is sleeveless like a jumper dress. However, the former is intended to be worn without a layering blouse in hot weather, while the latter may be worn during any time of year. The distinction between a jumper dress and an apron dress is less clear cut and in some cases either term is correct. If the design of the dress is directly inspired by an apron (having a bib in front, for example), the garment is often referred to as an apron dress.