gnarly (adj.)youdaoicibaDictYouDict[gnarly 词源字典]
"knotted and rugged," c. 1600, from gnarl (see gnarled) + -y (2). Picked up 1970s as surfer slang to describe a dangerous wave; it had spread to teen slang by 1982, where it meant both "excellent" and "disgusting."[gnarly etymology, gnarly origin, 英语词源]