A synonym for Repoussé. Embossing means creating a relief by raising the surface of sheet gold from the back. The term embossing is often used to indicate a certain mechanized way of working like using a die in contrast to Repoussé which is done with punches and hammers.
The image below shows an Etruscan breastplate with a relief created by embossing:
Embossed Etruscan Breastplate.