quaff (v.)youdaoicibaDictYouDict[quaff 词源字典]
1510s (implied in quaffer), perhaps imitative, or perhaps from Low German quassen "to overindulge (in food and drink)," with -ss- misread as -ff-. Related: Quaffed; quaffing. The noun is attested by 1570s, from the verb.[quaff etymology, quaff origin, 英语词源]