Décolletage

 
écolletage (or décolleté, its adjectival form, in current French) is the upper part of a woman's torso, between her waist and neck, comprising her neck, shoulders, back and chest, that is exposed by the style of her clothing. However, the term is most commonly applied to a neckline which reveals or emphasizes cleavage. Low-cut necklines are a feature of ball gowns, evening gowns, leotards and swimsuits, among other fashions. Although décolletage does not itself prescribe the extent of exposure of a woman's upper chest, the design of a décolleté garment takes into account current fashions, aesthetics, social norms and the social occasion when a garment will be worn, and exposing of nipples or areolae is almost always considered toplessness or partial nudity, and not considered socially acceptable in most modern cultures, though that has not always been the case.
Décolletage is a French word which is derived from decolleter, meaning to reveal the neck or, more literally, "without a collar".^[1] The term was first used in English literature sometime before 1831.^[2] In strict usage, décolletage is the neckline extending about two handbreadths from the base of the neck down, recto and verso.