Raster is a commonly used term in the field of graphic design, which refers to a grid or matrix of pixels that forms an image. Some synonyms for the word "raster" include bitmap, pixel map, and scan line image. The term "bitmap" refers to the process of creating an image by mapping individual pixels with binary values. The term "pixel map" describes the specific arrangement and organization of pixels within a raster image. "Scan line image" refers to a raster image that is constructed through the sequential scanning of a two-dimensional image grid. In summary, the synonyms of "raster" are interchangeable terms used to describe the specific characteristics of a digital image.