sandpaper
n//ˈsændˌpeɪpɚ//sandpapper, slippapper, slipark, sandpappra
(uncountable) Strong paper coated with (traditionally) sand or (today) manufactured aluminum oxide, silicon carbide, or other abrasive material, used for smoothing and polishing.
(countable) A sheet of such paper.
(transitive) To polish or grind (a surface) with or as if with sandpaper.