Cavo-rilievi is a word used to describe a type of sculpture that features images that are sunken into the surface of the material. There are several synonyms that can be used to describe cavo-rilievi, including intaglio, incised work, and sunken relief. Intaglio specifically refers to the use of a sharp tool to engrave or etch a design onto a surface, while incised work generally refers to a process of carving or cutting into a material. Sunken relief is similar to cavo-rilievi in that it involves creating a surface texture that is lower than the surrounding area, but it may not be as pronounced or intricate as cavo-rilievi.