nonanyoudaoicibaDictYouDict[nonan 词源字典]
"Of a fever: recurring every eighth day (by inclusive reckoning every ninth day)", Early 17th cent.; earliest use found in Philemon Holland (1552–1637), translator. From classical Latin nōnus ninth + -an, probably after French †nonane. Compare classical Latin nōnānus belonging to the ninth legion.[nonan etymology, nonan origin, 英语词源]