Décolletage is a plunging neckline on a woman's dress. Without decolletage, there would be no cleavage.
This French word comes from a verb meaning “expose the neck,” and that’s exactly what décolletage does: it’s a low neckline on a woman’s dress or shirt. Décolletage is revealing, and whether that’s sexy or sleazy is in the eye of the beholder. The opposite of décolletage would be a high neckline. People who know a lot about décolletage would include clothing designers and fashion observers. You’ll find décolletage aplenty on the red carpet at any Hollywood awards show.