vapid (adj.)youdaoicibaDictYouDict[vapid 词源字典]
1650s, "flat, insipid" (of drinks), from Latin vapidus "flat, insipid," literally "that has exhaled its vapor," related to vappa "stale wine," and probably to vapor "vapor." Applied from 1758 to talk and writing deemed dull and lifeless. Related: Vapidly; vapidness.[vapid etymology, vapid origin, 英语词源]