grotty (n.)youdaoicibaDictYouDict[grotty 词源字典]
slang shortening of grotesque, it had a brief vogue 1964 as part of the argot popularized by The Beatles in "A Hard Day's Night." It unconsciously echoes Middle English groti "muddy, slimy," from Old English grotig "earthy," from grot "particle."[grotty etymology, grotty origin, 英语词源]