decolletage

noun

1. the neckline of a dress cut low in the front or back and often across the shoulders.
2. a décolleté garment or costume.

noun

1. a low-cut neckline or a woman’s garment with a low neck

n.

1894 (from 1883 as a French word in English), from French décolletage, from décolleté “low-necked” (see decollete).