RASTER

[ras.ter] n [G, fr. L raster, rastrum rake, fr. radere to scrape] (1934): a scan pattern (as of the electron beam in a cathode-ray tube) in which an area is scanned from side to side in lines from top to bottom; also: a pattern of closely spaced rows of dots that form the image on a cathode-ray tube (as of a television or computer display)