décolletage

noun2

1. •
   A low neckline on a woman's dress, especially one that reveals or emphasizes her cleavage.
2. •
   The portion of a woman's body that is revealed by a low neckline; the upper chest, as well, sometimes, as the neck, and shoulders.

   • I visualized businessmen trying to see the tops of her stockings or into the valley of her décolletage as she bent to put drinks on a table. — 2011