Cavo rilievo is an Italian term that translates to "raised hollow." While there may not be a direct English synonym for this term, there are several phrases that can be used to convey a similar meaning. One such term is "sunken relief" which refers to a sculpture or artwork where the design is carved downward into the surface. Another synonym for cavo rilievo is "intaglio," which is the Italian term for engraving. This refers to a method of carving or printing where the design is cut into the surface of the material. Other potential synonyms for cavo rilievo include "concave relief," "shallow carving," or "recessed design".