grainy (adj.)youdaoicibaDictYouDict[grainy 词源字典]
1610s, "full of grains," from grain + -y (2). Photographic sense is from 1900. In Middle English, grain also was used as an adjective, "like grain, lumpy, spotted" (early 15c.). Related: Graininess.[grainy etymology, grainy origin, 英语词源]