Curvilinear perspective refers to the use of curved lines in artwork to create a sense of depth and volume. However, there are several synonyms for this term that can be used interchangeably. One such synonym is "oblique perspective," which refers to the use of diagonal lines to create depth and spatial relationships. Another synonym is "foreshortening," which refers to the technique of manipulating proportions to create the illusion of depth and distance. Lastly, "anamorphic perspective" is a type of curvilinear perspective that distorts the image to create a different perspective when viewed from a specific angle. Each of these synonyms refers to the art of creating three-dimensional illusions on a two-dimensional surface.