nubilousyoudaoicibaDictYouDict[nubilous 词源字典]
"Clouded in appearance; foggy, misty", Mid 16th cent.; earliest use found in John Bellenden (c1495–a1548), poet and translator. Either from classical Latin nūbilōsus cloudy (2nd cent. a.d.; from nūbilus + -ōsus), or from classical Latin nūbilus cloudy, dim, confused (from nūbēs cloud (perhaps cognate with Baluchi nōd) + -ilus, suffix forming adjectives) + -ous.[nubilous etymology, nubilous origin, 英语词源]